Vitamin D amine and amide derivatives

ABSTRACT

The invention relates to vitamin D amine and amide derivatives of general formula ##STR1## where R represents a hydrogen atom, an aliphatic, cycloaliphatic or araliphatic group, or an acyl group comprising an aliphatic, cycloaliphatic, arylaliphatic or aryl group linked to the nitrogen atom by way of a carbonyl group; R 1  and R 2  are each selected from lower alkyl and cycloalkyl groups or together with the carbon atom to which they are attached form a lower cycloalkyl group; R 3  represents a methyl group having α- or β-configuration; Y represents a lower alkylene, alkenylene or alkynylene group optionally substituted by a hydroxyl, etherified hydroxyl or esterified hydroxyl group; and A═ represents a cyclohexylidene moiety characteristic of the A-ring of a 1 α-hydroxylated vitamin D or analogue thereof. Active compounds of the invention exhibit cell modulating activity and in certain cases may also have an effect on calcium metabolism. The compounds of the invention may be prepared by isomerizing a 5,6-trans isomer of formula (I) to a corresponding 5,6-cis isomer; by hydroxylating a 1-unsubstituted-5,6-trans analogue of a compound of formula (I) to prepare a 5,6-trans isomer of formula (I); by reacting a compound containing a precursor for the desired 17-position side chain in one or more stages and with one or more reactants serving to form the desired side chain; or by reacting a compound of formula (I) to modify the substitution pattern about the A═ group.

This invention relates to novel vitamin D analogues, more particularlyto 1α-hydroxy vitamin D₃ analogues having a modified side chain at the17-position.

Vitamin D₃, which has the formula ##STR2## is well known to play a vitalrole in the metabolism of calcium, by promoting intestinal absorption ofcalcium and phosphorus, maintaining adequate serum levels of calcium andphosphorus and stimulating mobilisation of calcium from the bone fluidcompartment in the presence of parathyroid hormone.

It was learned more than 20 years ago that the D vitamins undergohydroxylation in vivo, hydroxylation at the 25-position occurring in theliver and hydroxylation at the 1α-position occurring in the kidney, theresulting 1α,25-dihydroxy metabolite being the biologically activematerial. This discovery led to the synthesis of many analogues ofvitamin D, evaluation of which indicated that hydroxyl groups at the1α-position a and at either the 24R- or the 25-position were essentialfor a compound or metabolite thereof to exhibit a substantial effect oncalcium metabolism. While, as indicated above, such hydroxyl groups willnormally ultimately be introduced in vivo, hydroxylation at the 24R- or25-position occurring rather more readily than at the 1α-position, theuse of vitamin D analogues already so hydroxylated has proved ofsubstantial advantage by virtue of their enhanced levels of activity andtheir rapidity of action and subsequent elimination from the body. Itwill be appreciated that 1α-hydroxylated vitamin D derivatives are ofespecial benefit to patients suffering from renal failure.

Examples of hydroxylated vitamin D analogues in current use include thenatural metabolite 1α,25-dihydroxy vitamin D₃ and 1α-hydroxy vitamin D₃(which is readily 25-hydroxylated in vivo). Other reportedly promisingcompounds include 1 α,24R-dihydroxy vitamin D₃, D₂ analogues of theabove compounds and 1α,25-dihydroxy analogues carrying fluorine atoms atthe 24-, 26- and/or 27- positions (see De Luca and Schnoes, Ann. Rev.Biochem. (1983), 52, pp 411-439 and De Luca et al., Top. Curr. Chem.(1979), 83, pp 1-65).

More recently it has been learned that the natural metabolite1α,25-dihydroxy vitamin D₃ has additional effects on cellularmetabolism. These cell modulating effects include stimulation of cellmaturation and differentiation (Tanaka et al., Biochem. J. (1982), 204,pp 713-719; Amento et al., J. Clin. Invest, (1984),73, pp 731-739;Colston et al., Endocrinology (1981), 108, pp 1083-1086; Abe et al.,Proc. Nat, Acad. Sci. (1981), 78, pp 4990-4994) and immunosuppressiveeffects (e.g. inhibition of interleukin II production) (Rigby,Immunology Today (1988), 9, pp 54-58).

Still more recently, an immunopotentiating effect of 1α,25-dihydroxyvitamin D₃ has been observed, the compound having been found tostimulate the production of bactericidal oxygen metabolites and thechemotactic response of leukocytes (see, for example, Cohen et al., J.Immunol. (1986), 136, pp 1049-1053). It is well known that leukocytesplay a major role in the body's defence against various infections (see,for example, Roitt, Brostoff and Male, "Immunology" 2nd Ed. (1989), C.V. Mosby, St. Louis, sec 16.10-16.13 and 17.4-17.5), e.g. by adhering toand engulfing invading organisms (chemotactic response) and/or byproducing superoxides and/or other toxic oxygen metabolites. It is knownthat this response may also be stimulated by mitogens such as theco-carcinogenic phorbal esters and γ-interferon, which are structurallyquite different from vitamin D analogues.

By virtue of these effects on cellular metabolism, 1α,25-dihydroxyvitamin D₃ in principle has therapeutic potential in such diverse areasas treatment of psoriasis, inflammatory and autoimmune diseases,neoplasias and hyperplasias, as an adjunct in the chemotherapy ofinfections (inter alia bacterial, viral and fungal), and in othertherapeutic modalities in which mononuclear phagocytes are involved.1α,25-dihydroxy vitamin D₃ and 1α-hydroxy vitamin D₃ have also beenproposed for use in the treatment of hypertension (Lind et al., ActaMed. Scand. (1987), 222, pp 423-427) and diabetes mellitus (Inomata etal., Bone Mineral (1986), 1, pp 187-192), and it has been suggested that1α,25-dihydroxy vitamin D₃ may promote hair growth (Lancet, 4 Mar. 1989,p 478) and may be useful in the treatment of acne (Malloy et al.,Tricontinental Meeting for Investigative Dermatology, Washington, 1989).

The potent effects of 1α,25-dihydroxy vitamin D₃ and 1α-hydroxy vitaminD₃ on calcium metabolism will, however, normally preclude such uses,since dosages at a level sufficient to elicit a desired cell modulating,immunosuppressive or immunopotentiating effect tend to lead tounacceptable hypercalcaemia. This has led to attempts to synthesize newanalogues having reduced effects on calcium metabolism but which stillexhibit the desired effects on cellular metabolism.

There have been reports of new analogues which exhibit, to at least amoderate degree, this desired separation of activity. Thus the compoundMC-903 (calcipotriol), which is a 22,23-unsaturated 1α,24R-dihydroxyvitamin D₃ analogue carrying a cyclopropyl group at the 24-positioninstead of the usual C_(25-C) ₂₇ configuration of the cholestane sidechain, and which is now used for the treatment of psoriasis, is reportedto exhibit an effect on cell maturation comparable in magnitude to1α,25-dihydroxy vitamin D₃, while exhibiting a smaller hypercalcaemiceffect (Calverley, Tetrahedron (1987), 43, pp 4609-4619; and Holick,Arch, Dermatol. (1989), 125, pp 1692-1696). Similar claims have beenmade for analogues of 1α,25-dihydroxy vitamin D₃, e.g. the 22-oxa (Abeet al., Endocrinology (1989), 124, pp 2645-2647), the 24- and the 26-homo (Ostrem et al., J. Biol, Chem. (1987), 262, pp 14164-14171), the16-dehydro- 23,24-ethynyl (Zhou et al., Blood (1989), 74, pp 82-93) andthe 19-nor-1-dihydro (Perlman et al., Tetrahedron Lett. (1990), pp1823-1824).

Other analogues of 1α,25-dihydroxy vitamin D₃ which have been studiedwith the aim of achieving enhanced separation ofdifferentiation-inducing activity and hypercalcaemic effect include23-oxa, 23-thia and 23-aza derivatives (Kubodera et al., Chem. Pharm.Bull. (1991), 39, pp 3221-3224), 22-oxa analogues bearing side chains ofdifferent sizes (Kubodera et al., Chem. Pharm. Bull. (1992), 40, pp1494-1499), and 20-epi analogues (Binderup et al., BiochemicalPharmacology (1991), 42, pp 1569-1575).

It does not appear possible to deduce from these disclosures eitherwhich compounds will exhibit cell modulating activity(or the level ofany such activity) or to determine factors which lead to a separation ofactivities as regards cell modulation and calcium metabolism. Thus, forexample, it has been observed that there are no strict relationshipsbetween differentiation-inducing activity and side chain length orhydrophilicity.

The majority of results suggest that the presence of a hydroxyl grouptowards the end of a cholestane-type side chain or homologue thereof isnecessary for compounds to show significant cell modulating activity.However, the findings of Ostrem et al. (op. cit.) indicate thatanalogues having only a short, unsubstituted 17-position side chain(e.g. isopropyl or sec-butyl, as in homo- or bis-homo-pregnanes) exhibitquite substantial-differentiation-inducing activity and are more potentthan corresponding short side chain compounds bearing a side chainhydroxyl group.

A number of the proposed analogues appear to show cell modulatingactivity at a similar level to that of 1α,25-dihydroxy vitamin D₃, butalso appear still to show appreciable effects on calcium metabolism,such activity being attenuated by at most two orders of magnituderelative to that of 1α,25-dihydroxy vitamin D₃. Moreover, it now appearsin the case of many, if not all, of the new analogues described above asexhibiting separation of calcium and cellular metabolic effects,including MC-903, that the attenuated calcium effect may be due merelyto more rapid metabolism of the vitamin reducing the amount of thecirculating drug (see e.g. Bouillon et al., J. Bone Miner. Res. (1991),6, p 1051 and Dusso et al., Endocrinology (1991), 128, p 1687). This maysimilarly reduce the cell modulating effect in vivo so that one mayrequire larger systemic dosages than are suggested by in vitro testresults.

Use of such analogues may therefore give rise to cumulative toxicityproblems if the compounds are used in long term therapy, particularlywhere systemic application is required, e.g. for treatment ofinflammatory and autoimmune diseases, neoplasias and hyperplasias, or inoral therapy for treatment of psoriasis, and there is thus a continuingneed in such areas of therapy for vitamin D-like compounds which exhibitpotent cell modulating activity coupled with a reduced effect on calciummetabolism.

There may also be circumstances in which a particular balance of cellmodulating and calcium metabolising properties is desired. This may bethe case in, for example, the treatment of osteoporosis. The presentinvention is based on the finding that 1α-hydroxy vitamin D derivativesin which the 17-position side chain carries certain amine or amidefunctions may exhibit useful biological activity; this is mostsurprising in that the invention includes is compounds which lack a sidechain hydroxyl group; such a group has hitherto normally been thoughtdesirable in order to promote calcaemic and/or cell modulating activity.Furthermore, as noted by Kubodera et al. (op. cit., 1991), introductionof a nitrogen atom into the 17-position side chain of 1α,25-dihydroxyvitamin D₃ to replace a methylene group thereof appears to bedeactivating as regards differentiation-inducing activity. One mighttherefore expect replacement of the activity-promoting side chainhydroxyl group of a vitamin D analogue by an amine or amide function tobe even more deactivating, especially since amine groups are verysignificantly more basic than oxygen functions such as hydroxyl groups,and are protonated at physiological pH.

Additionally, as is described in greater detail hereinafter, it has beenfound that by appropriate selection of e.g. the size of the carbon chainof the 17-position side chain of the compounds according to theinvention it is possible to influence their activity by enhancing eithercell modulating properties or activity as regards calcium metabolism andbone calcium mobilisation, thereby making possible the preparation ofcompounds with particular activity profiles suited to particulartherapeutic applications.

Thus according to one aspect of the present invention there are providedcompounds of formula (I) ##STR3## (where R represents a hydrogen atom,an aliphatic, cycloaliphatic, araliphatic or aryl organic group, or anacyl group comprising such an organic group linked to the nitrogen atomby way of a carbonyl group; R¹ and R², which may be the same ordifferent, each represent a lower alkyl or cycloalkyl group or togetherwith the carbon atom to which they are attached form a lower cycloalkylgroup; R³ represents a methyl group having αa-or β-configuration; Yrepresents a lower alkylene, alkenylene or alkynylene group optionallysubstituted by a hydroxyl, etherified hydroxyl or esterified hydroxylgroup; and A═ represents a cyclohexylidene moiety characteristic of theA-ring of a 1α-hydroxylated vitamin D or analogue thereof.

Where either of R¹ and R² represent lower alkyl groups these may, forexample, be C₁₋₆ alkyl groups such as methyl, ethyl, propyl and butylgroups. Lower cycloalkyl groups R¹ and R² may, for example, contain 3-8carbon atoms, e.g. as in cyclopropyl, cyclopentyl and cyclohexyl groups.

Where R represents an aliphatic or cycloaliphatic group this may, forexample, be a lower alkyl or lower cycloalkyl group, e.g. as describedfor R¹ and R². Araliphatic groups R may, for example, include C₆₋₁₂carbocyclic aryl C₁₋₄ alkyl groups such as benzyl or phenethyl; arylgroups may, for example, include C₆₋₁₂ carbocyclic aryl groups such asphenyl or naphthyl. Where R represents an acyl group this may, forexample, be a lower (e.g. C₁₋₆) alkanoyl group such as formyl, acetyl orpropionyl; a C₆₋₁₂ carbocyclic aryl C₂₋₅ alkanoyl group such asphenylacetyl; or a C₇₋₁₃ carbocyclic aroyl group such as benzoyl. Thegroup R may optionally carry one or more substituents, for exampleselected from halo (e.g. chloro or bromo), lower (e.g. C₁₋₄) alkyl suchas methyl, lower alkoxy (e.g. methoxy), lower alkanoyl (e.g. acetyl),lower alkylamino (e.g. methylamino), di(lower alkyl)amino (e.g.dimethylamino), nitro, carbamoyl and lower alkanoylamino (e.g.acetamido).

Lower alkylene, alkenylene or alkynylene groups represented by Y may,for example, contain up to 7 carbon atoms and up to 3 multiple bonds. Ymay advantageously be a straight chained group, e.g. containing 3-6carbon atoms, for example as in trimethylene, tetramethylene,pentamethylene, hexamethylene, buta-1,3-dienylene, propynylene,but-1-ynylene or but-2-ynylene.

Where Y is substituted by a hydroxyl, etherified hydroxyl or esterifiedhydroxyl group, this substituent may advantageously be positioned α-, β-or γ- to the group --C(R¹) (R²) .NHR or α- to any triple bond present inthe group Y. Etherified hydroxyl groups which may be present inclkudelower (e.g. C₁₋₆) alkyl groups optionally interrupted by one or moreoxygen atoms (e.g. methyl, methoxymethyl or methoxyethoxymethyl), andcyclic groups such as tetrahydropyranyl. Esterified hydroxyl groupswhich may be present include lower (e.g. C₁₋₆) alkanoyl such as acetyl,propionyl, isobutyryl or pivaloyl; lower alkenoyl (e.g. allylcarbonyl);aroyl (e.g. p-nitrobenzoyl); lower alkoxycarbonyl (e.g.t-butoxycarbonyl); lower haloalkoxycarbonyl (e.g.2,2,2-trichloroethoxycarbonyl or1,1,1-trichloro-2-methyl-2-propoxycarbonyl); aralkyloxycarbonyl (e.g.benzyloxycarbonyl or p-nitrobenzyloxycarbonyl); and loweralkenyloxycarbonyl (e.g. allyloxycarbonyl). It will be appreciated thatit may be advantageous to select etherifying or esterifying groups whichare metabolically labile in vivo.

Where R³ in formula (I) is a methyl group in the α-configuration thecompounds have the 20R configuration characteristic of natural vitamin Dderivatives; where R¹ is in the β-configuration the compounds have the20S configuration of epi-vitamin D derivatives. It will be appreciatedthat the invention also embraces mixtures of the two isomers.

The cyclohexylidene ring represented by A═ will normally carry hydroxylgroups or protected derivatives thereof at the 1α- and 3β-positions, andmay carry further substituents, e.g. which tend to enhance calcaemic orantiproliferative activity and/or stimulate differentiation. A═ maythus, for example, be represented by the formula (A-1) ##STR4## where R⁴and R⁵, which may be the same or different, each represent a hydrogenatom or an 0-protecting group, and R⁶ and R⁷, which may the same ordifferent, are selected from hydrogen atoms and appropriate mono- ordi-valent substituting groups.

Where R⁴ and R⁵ represent O-protecting groups these may, for example, becleavable O-protecting groups such as are commonly known in the art.Suitable groups include etherifying groups such as silyl groups (e.g.tri (lower alkyl) silyl groups such as trimethylsilyl, triethylsilyl,triisopropylsilyl or t-butyldimethylsilyl; tri (aryl) silyl groups suchas triphenylsilyl; and mixed alkyl-arylsilyl groups); lower (e.g. C₁₋₆)alkyl groups optionally interrupted by an oxygen atom, such as methyl,methoxymethyl or methoxyethoxymethyl; and cyclic groups such astetrahydropyranyl. Esterifying O-protecting groups include lower (e.g.C₁₋₆) alkanoyl such as acetyl, propionyl, isobutyryl or pivaloyl; aroyl(e.g. containing 7-15 carbon atoms) such as benzoyl or4-phenylazobenzoyl; lower alkane sulphonyl such as (optionallyhalogenated) methane sulphonyl; and arene sulphonyl such as p-toluenesulphonyl.

O-protected derivatives are useful as intermediates in the preparationof active 1α,3β-diols of formula (I) where R⁴ and R⁵ represent hydrogenatoms. Additionally, where the O-protecting groups are metabolicallylabile in vivo, such ethers and esters of formula (I) may be usefuldirectly in therapy.

At least one of R⁶ and R⁷ is advantageously a hydrogen atom.Substituents which may be present as the. other of R⁶ and R⁷ include,for example, methylene, methyl and ethylene (so as to form aspiro-linked cyclopropyl group with the attached carbon atom).

Representative A═ groups falling within the above formula A-1) includethe following: ##STR5##

It will be appreciated that compounds containing groups (A-2) and (A-3)are respectively 5,6-cis (i.e. 5 Z) and 5,6-trans (i.e. 5 E) isomers ofvitamin D analogues. Compounds containing groups (A-4) and (A-5) aresimilarly 5,6-cis and 5,6-trans isomers respectively of 10,19-dihydrovitamin D analogues, and compounds containing group (A-8) are 19-norvitamin D analogues.

5,6-Trans isomers according to the invention are principally of interestas intermediates in the preparation of corresponding 5,6-cis isomers,e.g. as described in greater detail hereinafter. However, 5,6-transisomers in which R⁴ and R⁵ are hydrogen atoms or metabolically labilegroups will often exhibit biological activity, e.g. at about one orderof magnitude less than corresponding 5,6-cis isomers, and may thus beuseful in therapy.

Active compounds of formula (I) in which Y is, for example, a groupcontaining up to 3 carbon atoms such as trimethylene and R¹ and R² are,for example, lower alkyl groups such as methyl or ethyl may exhibitsimilar activity to known 1α-hydroxy vitamin D derivatives such as1α,25-dihydroxy vitamin D₃. Thus, for example, such compounds mayexhibit a significant effect on calcium metabolism, e.g. by stimulatingintestinal calcium transport, bone calcium mobilisation and boneformation. These compounds may therefore have applications in, forexample, treatment and/or prevention of disorders such as rickets andosteomalacia, osterporosis, hypoparathyroidism, hypophosphateamia,hypocalcaemia and/or associated bone disease, hypocalcaemic tetany,renal failure and disorders such as renal osteodystrophy, biliarycirrhosis and steatorrhea, and secondary hypocalcaemia and/or bonedisease arising from disfunction of the liver, kidneys orgastrointestinal tract or resulting from treatment with dilantin,barbiturates such as phenylbarbitone and related drugs; they may beparticularly useful in treating disorders which are refractory tonatural compounds such as vitamin D₃.

The presence of an amino group in compounds of formula (I) in which Rrepresents hydrogen or a lower alkyl group may enhance thebioavailability of the compounds relative to vitamin D derivativescontaining a side chain hydroxyl group, for example by limitingsequestration in liposomes, and may also permit the compounds readily tobe formulated as aqueous compositions, a highly advantageous propertycompared to conventional oil-soluble vitamin D derivatives.

The above-described compounds of formula (I) also exhibit cellmodulating activity, e.g. as evidenced by eliciting cell differentiationand maturation, inhibiting proliferation and/or by activating monocytes(e.g. as estimated by the method of Styrt et al., Blood (1986), 67, pp334-342), but their calcaemic effects may be too pronounced to permite.g. mid- or long-term use in respect of their cellular metaboliceffects. The higher homologues of these compounds, however, e.g.compounds (I) in which Y contains 4-7 carbon atoms and/or R¹ and/or R²each contain 2 or more carbon atoms, may tend to exhibit a reducedeffect on calcium metabolism, e.g. as evidenced by low effects on serumcalcium and phosphorus levels in rats, and may accordingly exhibit anadvantageous therapeutic ratio of cell modulating to calcaemic activity.

The cell modulating activity of such active compounds according to theinvention, combined with a substantial lack of calcaemic effect, renderthem of interest (both alone and as adjuncts) in the management ofneoplastic disease, particularly myelogenous leukemias, and suggesttheir use as agents to promote wound healing. They may also be usedeither alone or as adjuncts in the chemotherapy of infection and in allother therapeutic modalities in which mononuclear phagocytes areinvolved, for example in treatment of bone disease (e.g. osteoporosis,osteopenia and osteodystrophy as in rickets or renal osteodystrophy),autoimmune diseases, host-graft reaction, transplant rejection,inflammatory diseases (including modulation of immunoinflammatoryreactions), neoplasias and hyperplasias, myopathy, enteropathy andspondylitic heart disease. Such active compounds according to theinvention may also be useful in suppression of parathyroid hormone (e.g.as in serum calcium homeostasis), in treatment of dermatologicaldiseases (for example including acne, alopecia, eczema, pruritus,psoriasis and skin aging, including photoaging), hypertension,rheumatoid arthritis, psoriatic arthritis, secondary hyperparathyrodism,asthma, cognitive impairment and senile dementia (including Alzheimer'sdisease), in fertility control in both human and animal subjects, and inmanagement of disorders involving blood clotting, e.g. by dissolution ofexisting clots and/or prevention of clotting. The invention embraces useof these compounds in the therapy or prophylaxis of such conditions andin the manufacture of medicaments for such treatment or prophylaxis.

We believe that the active 20R isomers of such compounds of formula (I)may be preferred for treatment of infections, e.g. in combinationtherapy, whereas the active 20S epi-isomers may be preferred forapplications involving an immunosuppressive effect, e.g. in treatment ofautoimmune and inflammatory diseases, rheumatoid arthritis, asthma etc.This view is supported by, for example, the work of Binderup et al.concerning 20-epi-vitamin D₃ analogues reported in BiochemicalPharmacology (1991), 42(8), pp 1569-1575.

It will be appreciated that it may be preferred to select lowerhomologues according to formula (I) for treatment of e.g. defects ofcalcium metabolism and to select higher homologues specifically fortheir cell modulating activity, e.g. in treatment of hyperplasias suchas psoriasis. However, both types of activity may be useful in, forexample, treatment of bone disease, and particular homologues maytherefore be chosen by selection of appropriate meanings for Y, R¹ andR² in order to give a desired balance of activities for such purposes.

It has been reported (Neef et al., 9th Workshop on Vitamin D (1994) thatin the case of vitamin D compounds having conventional terminallyhydroxylated 17-position side chains (including side chains containing aheteroatom at the 23-position), analogues having 20,20-dimethyl,20-methylene or 20-spirocyclopropyl groups may exhibit useful biologicalactivity, typically resembling that of the corresponding 20Rmethyl-substituted isomer rather than the corresponding 20S epi-isomer.The present invention embraces analogues of the above-defined compoundsof formula (I) wherein R³ is selected from dimethyl, methylene andspirocyclopropyl groups.

Active compounds according to the invention may be formulated foradministration by any convenient route, e.g. orally (includingsublingually), parenterally, rectally or by inhalation; pharmaceuticalcompositions so formulated comprise a feature of the invention.

Orally administrable compositions may, if desired, contain one or morephysiologically compatible carriers and/or excipients and may be solidor liquid. The compositions may take any convenient form including, forexample, tablets, coated tablets, capsules, lozenges, aqueous or oilysuspensions, solutions, emulsions, syrups, elixirs and dry productssuitable for reconstitution with water or another suitable liquidvehicle before use. The compositions may advantageously be prepared indosage unit form. Tablets and capsules according to the invention may,if desired, contain conventional ingredients such as binding agents, forexample syrup, acacia, gelatin, sorbitol, tragacanth orpolyvinyl-pyrollidone; fillers, for example lactose, sugar,maize-starch, calcium phosphate, sorbitol or glycine; lubricants, forexample magnesium stearate, talc, polyethylene glycol or silica;disintegrants, for example potato starch; or acceptable wetting agentssuch as sodium lauryl sulphate. Tablets may be coated according tomethods well known in the art.

Liquid compositions may contain conventional additives such assuspending agents, for example sorbitol syrup, methyl cellulose,glucose/sugar syrup, gelatin, hydroxymethylcellulose,carboxymethylcellulose, aluminium stearate gel or hydrogenated ediblefats; emulsifying agents, for example lecithin, sorbitan monooleate oracacia; non-aqueous vehicles, which may include edible oils, for examplevegetable oils such as arachis oil, almond oil, fractionated coconutoil, fish-liver oils, oily esters such as polysorbate 80, propyleneglycol, or ethyl alcohol; and preservatives, for example methyl orpropyl p-hydroxybenzoates or sorbic acid. Liquid compositions mayconveniently be encapsulated in, for example, gelatin to give a productin dosage unit form.

Compositions for parenteral administration may be formulated using aninjectable liquid carrier such as sterile pyrogen-free water, sterileperoxide-free ethyl oleate, dehydrated alcohol or propylene glycol or adehydrated alcohol/propylene glycol mixture, and may be injectedintravenously, intraperitoneally or intramuscularly.

Compositions for rectal administration may be formulated using aconventional suppository base such as cocoa butter or another glyceride.

Compositions for topical administration include ointments, creams, gels,lotions, shampoos, paints, powders (including spray powders), pessaries,tampons, sprays, dips, aerosols, pour-ons and drops. The activeingredient may, for example, be formulated in a hydrophilic orhydrophobic base as appropriate.

Compositions for administration by inhalation are convenientlyformulated for self-propelled delivery, e.g. in metered dose form, forexample as a suspension in a propellant such as a halogenatedhydrocarbon filled into an aerosol container provided with a meteringdispense valve.

It may be advantageous to incorporate an antioxidant, for exampleascorbic acid, butylated hydroxyanisole or hydroquinone in thecompositions of the invention to enhance their storage life.

Where any of the above compositions are prepared in dosage unit formthese may for example contain 0.1-500 μg, e.g. 0.2-100 μg, of activecompound according to the invention per unit dosage form. Thecompositions may if desired incorporate one or more further activeingredients.

A suitable daily dose of an active compound according to the inventionmay for example be in the range 0.2-1000 μg, e.g. 0.4-200 μg, per day,depending on factors such as the severity of the condition being treatedand the age, weight and condition of the subject.

Compounds according to the invention may be prepared by any convenientmethod, for example one of the following:

A) 5,6-Cis compounds of formula (I) may be prepared by isomerisation ofa corresponding 5,6-trans compound, followed if necessary and/or desiredby removal of any O-protecting groups. Isomerisation may be effected by,for example, treatment with iodine, with a disulphide or diselenide, orby irradiation with ultraviolet light, preferably in the presence of atriplet sensitiser.

B) 5,6-Trans compounds of formula (I) may be prepared by hydroxylating acorresponding 1-unsubstituted-5,6-trans compound, e.g. a compound (I)having an A═ group of the formula ##STR6## (where R⁴ is hydrogen or anO-protecting group). Such hydroxylation may be effected using a seleniteester (which may be generated in situ by reaction of selenium dioxide orselenous acid and an alcohol), e.g. as described in GB-A-2038834, orusing selenous acid at a pH in the range 3-9, e.g. as described inGB-A-2108506; the contents of both these specifications are incorporatedherein by reference. The 1-unsubstituted-5,6-trans compound may, ifdesired, be prepared by isomerisation of the corresponding 5,6-cisvitamin in situ under the conditions of the hydroxylation reaction,which may be followed by isomerisation and/or removal of O-protectinggroups as necessary and/or desired.

C) By reaction of a compound containing a precursor for the desired17-position side chain in one or more stages and with one or morereactants serving to form the desired side chain, followed if necessaryand/or desired by isomerisation and/or removal of O-protecting groups.

Thus, for example, in order to prepare a compound (I) in which R¹ and R²are the same, a compound of general formula (II) ##STR7## (where R³, Yand A═ are as hereinbefore defined, A═ preferably being one of thegroups (A-2)-(A-8) in O-protected form) may be reacted with anorgano-cerium reagent, e.g. prepared in situ from cerous chloride and anappropriate organometallic compound, e.g. an alkyl/cycloalkyl lithiumcompound of formula R¹ Li (where R¹ is as hereinbefore defined), forexample as described by Ciganek (J. Ora. Chem. (1992), 5, pp 4521-4527).

Compounds of formula (I) in which R¹ and R² are different may, forexample, be prepared by reacting a thio-oxime of formula (III) ##STR8##(where R¹, R³, Y and A═ are as hereinbefore defined and R⁸ is anaromatic group, e.g. a carbocyclic aryl group such as phenyl) with anappropriate organometallic compound, for example an alkyl/cycloalkyllithium compound of formula R² Li (where R² is as hereinbefore defined),and reducing the thus-obtained compound of formula (IV) ##STR9## (whereR¹, R², R³ ₁ R⁸, Y and A═ are as hereinbefore defined), e.g. using ametal hydride reducing agent such as sodium borohyride or an inorganicor organic sulphur compound such as hydrogen sulphide, sodium sulphideor a thiol (e.g. a lower alkyl mercaptan such as methanethiol) to removethe R⁸.S group and yield a corresponding compound of formula (I) inwhich R is a hydrogen atom (see J. Ora, Chem. (1977), 42, pp 398-399).

Compounds of formula (I) in which R represents a lower alkanoyl,aralkanoyl or aroyl group may be prepared by acylation of acorresponding compound (I) in which R is hydrogen, for example byreaction with an appropriate acyl halide or acid anhydride or with anappropriate acid in the presence of a coupling agent such asN,N'-carbonyl-diimidazole or dicyclohexylcarbodiimide. It will beappreciated that any hydroxyl groups present elsewhere in the molecule,e.g. as substituents of the A═ or Y groups, should desirably be inO-protected form during such acylation reactions.

Compounds of formula (I) in which R represents a lower alkyl group may,for example, be prepared by reducing a corresponding compound (I) inwhich R is a lower alkanoyl group, e.g. using a metal hydride reducingagent such as lithium aluminium hydride. Alternatively a compound (I) inwhich R represents a hydrogen atom may be subjected to directalkylation, e.g. by reaction with an alkyl halide, or to reductiveamination, e.g. by reaction with an appropriate aldehyde and a reducingagent such as sodium cyanoborohydride.

Compounds of formula (I) in which Y is an alkynylene group may, forexample, be prepared by reaction of a compound of formula (V) ##STR10##(where R³ and A═ are as hereinbefore defined; Y^(a) is an alkylenegroup, e.g. containing 1-4 carbon atoms; and L represents a leavinggroup, for example a sulphonate ester group, e.g. lower alkylsulphonyloxy such as mesyloxy, lower fluoroalkyl sulphonyloxy such astrifluoromethanesulphonyloxy or aryl sulphonyloxy such as tosyloxy, or ahalogen atom such as chlorine, bromine or iodine), with a metallatedderivative (e.g. the lithio derivative) of an alkyne of formula (VI)##STR11## (where R, R¹ and R² are as hereinbefore defined and n is 0 oran integer, e.g. in the range 1-3).

The thus obtained compound (I) in which Y is the group

    --Y.sup.a --C.tbd.C--(CH.sub.2).sub.n.sup.--

(wherein Y^(a) and n are as hereinbefore defined) may if desired behydrogenated to convert the triple bond either to a double bond (e.g.using Lindlar catalyst) or to a single bond (e.g. using a noble metalcatalyst such as platinum, palladium or homogeneous rhodium orruthenium). During such hydrogenations the 5,7-diene or5,7,10(19)-triene system of the compound (I) is preferably protected byformation of a Diels Alder adduct by reaction with a dienophile, e.g. asdescribed in GB-A-2114570 (the contents of which are incorporated hereinby reference); preferred dienophiles include diacylazo compounds such asphthalazine diones and phenyl triazoline diones. The Diels Alder adductmay be removed, e.g. by ozonolysis or other oxidative techniques afterthe hydrogenation.

Compounds of formula (I) in which Y is an alkynylene group carrying ahydroxyl group α to the triple bond may, for example, be prepared byreaction of a compound of formula (VII) ##STR12## (where R³ and A═ areas hereinbefore defined and Y^(b) is a valence bond or an alkylenegroup, e.g. containing 1-4 carbon atoms) with a metallated derivative ofan alkyne of formula (VI), so as to form a compound (I) in which Y is agroup

    --Y.sup.b --CH (OH) --C.tbd.--C--(CH.sub.2).sub.n --

(wherein Y^(b) and n are as hereinbefore defined).

Compounds of the formula (VI) may be prepared by subjecting a compoundof formula (VIII)

    CH.sub.3 (CH.sub.2).sub.n C.tbd.C--C(R.sup.1)(R.sup.2)OH

(where n, R¹ and R² are as hereinbefore defined) to a Ritter reactionwith a compound of formula R^(a) CN (where R^(a) represents a hydrogenatom or an appropriate organic group) in the presence of a strong acid,e.g. a mineral acid such as sulphuric acid, thereby leading to formationof a compound (I) in which R represents a group R^(a).CO--. This groupmay be removed by hydrolysis to yield a compound (I) in which Rrepresents a hydrogen atom or may be reduced, e.g. as hereinbeforedescribed, to yield a compound (I) in which R represents a groupR^(a).CH₂ --. Alternatively the hydroxy group of the tertiary carbinolmay be displaced by an azido group, e.g. by reaction with hydrazoic acidin the presence of a strong acid, and the azido group reduced to yield acompound (I) in which R represents hydrogen. The internal alkyne maythen be isomerized to the terminal position by treatment with thepotassium salt of 1,3-propanediamine in 1,3-propanediamine as solvent("acetylene zipper").

Compounds of formula (II) may, for example, themselves be prepared byreaction of a compound of formula (V) as defined above with, asappropriate, (i) a source of cyanide ion (e.g. an alkali metal cyanidesuch as sodium or potassium cyanide), (ii) a metallated acetonitrilederivative (e.g. the lithio derivative), or (iii) acrylonitrile,preferably where L is an iodine atom (e.g. by ultrasound-inducedchromium-mediated conjugate addition as described by Mourino et al. in JOrg. Chem, (1993), 58, pp 118-123).

Compounds (II) in which the 17-position side chain terminates in thegroup --CH:CH.CN may, for example, be prepared from an aldehyde offormula (VI) as defined above by means of a Wittig reaction with an ylidof formula (R⁹)₃ P:CH.CN (where each R⁹ represents an organic group,e.g. a carbocyclic aryl group such as phenyl) or with a correspondingphosphonate or silyl equivalent.

Compounds of formula (III) may, for example, themselves be prepared byreacting a ketone of formula (X) ##STR13## (where R¹, R³, Y and A═ areas hereinbefore defined) with an S-substituted thiolamine of formulaR⁸.S.NH (where R⁸ is as hereinbefore defined). Such compounds of formula(IX) may be prepared from, for example, an acid of formula (X) ##STR14##(where R³, Y and A═ are as hereinbefore defined), e.g. by formation of acorresponding acid halide such as the chloride and reaction with anorganometallic compound R¹ MX (where R¹ is as hereinbefore defined; Mrepresents a divalent metal such as copper, zinc or cadmium; and Xrepresents e.g. a halogen atom). Alternatively one may prepare compounds(IX) by reacting a compound of formula (V) above with e.g. (i) anα-metallated derivative such as a lithio derivative of a ketone offormula CH₃.CO.R¹ (where R¹ is as hereinbefore defined) or with acorresponding enol, or (ii), preferably where L is an iodine atom, avinyl ketone of formula CH₂ :CH.CO.R¹ (where R¹ is as hereinbeforedefined), e.g. by ultrasound-induced chromium-mediated conjugateaddition as described by Mourino et al. (op. cit.).

Compounds (X) and esters thereof may also be used to prepare compoundsof formula (II) by reaction with ammonia or a metallated derivativethereof, e.g. an alkali metal amide such as lithium amide, to form acorresponding carboxamide which may be converted to a nitrile (II) bymild dehydration, e.g. using tosyl chloride, phosphorus oxychloride inthe presence of a base such as pyridine, or trifluoracetic anhydride inthe presence of an excess of a base such as pyridine.

Compounds (II) in which Y is α-substituted by a hydroxyl group areconveniently obtained by cyanohydrin formation, for example by reactionof a compound (VII) with hydrogen cyanide. Compounds (II) in which Y isβ-substituted by a hydroxyl group may be prepared directly by reactionof a compound (VII) with a metallated (e.g. lithated) derivative ofacetonitrile; they may also be prepared indirectly by reaction with ametallated derivative of an ester of acetic acid, followed by conversionof the ester group to a carboxamide group and then to a nitrile group,e.g. as described above.

In general compounds (I) and starting materials therefor in which Y issubstituted by a hydroxyl group may be converted to corresponding etherand ester derivatives by standard methods such as are well known in theart. Thus, for example, etherification may be effected by reaction withan appropriate organic halide (e.g. an alkyl iodide) in the presence ofan appropriate base (e.g. an alkali metal alkoxide such as potassiumt-butoxide), advantageously in the presence of a crown ether such as18-crown-6. Esterification may be effected by reaction with appropriateacylating agents, such as acyl halides, acid anhydrides and the like.

Useful starting materials for the above compounds of formulae (V), (VII)and (X) include compounds (XI) ##STR15## (where R⁴ and R⁵ are as definedabove) and/or 5,6-trans isomers thereof and the corresponding 1-deoxycompounds; such compounds may be obtained through oxidative cleavage(e.g. by ozonolysis) of the 22,23-double bond of vitamin D₂, 1α-hydroxyvitamin D₂ or O-protected derivatives thereof, these preferably beingstabilised by formation of a Diels Alder dienophile adduct, e.g. withsulphur dioxide or a diazacyclo compound, for example as described inGB-A-2114570 (the contents of which are incorporated herein byreference).

Such 20S compounds (XI), optionally still in the form of theirdienophile adducts, may be isomerised by, for example, treatment with amild base, e.g. an inorganic base such as sodium bicarbonate or atertiary organic base such as 1,4-diazabicyclo 2.2.2!octane ("DABCO") or1,8-diazabicyclo 5.4.0!undec-7-ene ("DBU"). This yields a mixture of 20Rand 20S isomers from which the pure 20R epi-isomer may be isolatedchromatographically; alternatively separation of a desired epi-isomermay be delayed until a later stage in the synthesis, up to and includingthe final step.

Reduction of the aldehyde grouping of a compound (XI) or a correspondingepi-isomer, e.g. using a metal hydride reducing agent such as sodiumborohydride, yields a corresponding hydroxymethyl compound, i.e. acompound (V) in which Y^(a) is CH₂ and L is OH. This may be converted toa compound (V) in which L is a leaving group by, for example, conversionto a sulphonate ester (e.g. to a tosylate) followed, if desired, bynucleophilic displacement of the sulphonate group by reaction with ahalide salt (e.g. an alkali metal bromide).

Compounds of formula (V) in which A═ represents a group (A-9) ashereinbefore defined, Y^(a) is as hereinbefore defined, and L representsan O-protected hydroxyl group (e.g. in which the hydroxyl group isesterified, for example with a lower alkanoyl group such as acetyl) maybe subjected to 1α-hydroxylation as described under (B) above to givecompounds (V) in which A═ represents a group (A-2) or (A-3) ashereinbefore defined in which R⁵ represents hydrogen. Such compounds orprotected derivatives thereof, e.g. in which R⁵ is trimethylsilyl, maybe hydrogenated (e.g. in the presence of a noble metal catalyst such astris-triphenylphosphine rhodium chloride) to yield correspondingcompounds in which A═ represents a group (A-4) or (A-5) as hereinbeforedefined, or may be cyclopropanated (e.g. by reaction with methyleneiodide in the presence of zinc/copper couple) to yield correspondingcompounds in which A═ represents a group (A-6) or (A-7) as hereinbeforedefined. Where appropriate, the compounds so obtained may be convertedto compounds in which R⁵ is an O-protecting group (e.g. by silylation)and may be hydrolysed (e.g. with base such as potassium hydroxide orpotassium carbonate) or reduced (e.g. with lithium aluminium hydride) toremove the side chain ester group to yield useful starting materials (V)in which L represents a hydroxyl group.

19-Nor analogues of compounds of formula (XI) and corresponding20-hydroxymethyl compounds (i.e. starting materials for compounds (I) inwhich A═ represents a group (A-8) as hereinbefore defined) may beprepared as described by Perlman et al., Tetrahedron Letters (1992), 33,pp 2937-2940.

Compounds of formula (V) in which Y^(a) is e.g. ethylene or trimethylenemay, for example, be obtained by reaction of a compound (V) in whichY^(a) is methylene either (i) with a reagent serving to introduce aone-carbon fragment (e.g. a metal cyanide) and conversion of the groupso introduced to a group --CH₂ L, e.g. by hydrolysing a cyano group toyield a carboxy group or by reducing such a cyano group (e.g. with ametal hydride reducing agent such as diisobutyl aluminium hydride) toyield a carboxaldehyde group, and reducing the carboxy or carboxaldehydegroup (e.g. using sodium borohydride or lithium aluminium hydride) toyield a hydroxymethyl group which may in turn be subjected to tosylationand, if desired, nucleophilic displacement as hereinbefore described toeffect conversion to a halomethyl group; or (ii) with a metallatedderivative of an ester or thioester of acetic acid, with a derivativecontaining another carbanionic equivalent of acetic acid (e.g. ametallated derivative of acetonitrile), or with a metallated malonateester (in which last instance the reaction product is partiallyhydrolysed to yield a monoester which may be decarboxylated by heatingto yield a carboxylate ester), reducing the resulting ester or thioesterproduct to an alcohol (e.g. using lithium aluminium hydride), andconverting the resulting hydroxyl group to a leaving group, such as atosylate group or a halogen atom, e.g. as hereinbefore described.

It will be appreciated that the above procedures (i) and/or (ii) may berepeated as needed to yield compounds (V) in which Y^(a) is a C₃ -C₇alkylene group. D) By reaction of a compound of formula (I) to modifythe substitution pattern about the A═ group, followed if necessaryand/or desired by isomerisation and/or removal of protecting groups.

Thus for example, compounds (I) in which A═ represents a group (A-4) or(A-5) may be prepared by hydrogenation of corresponding compounds inwhich A═ represents (A-2) or (A-3), e.g. using the method ofGB-A-1583749. It will be appreciated that such hydrogenation mayalternatively be effected at an earlier stage of a reaction sequence,e.g. on a starting material or intermediate of formula (V).

Compounds (I) in which A═ represents a group (A-6) or (A-7) may beprepared from corresponding compounds in which A═ represents (A-2) or(A-3) (in which R⁴ is an O-protecting group and R⁵ is a hydrogen atom ora trimethylsilyl group) by Simmons-Smith methylenation (see e.g. Neef etal., Tetrahedron Letters (1991), 32, pp 5073-5076).

Compounds (I) in which A═ represents a group (A-8) may, for example, beprepared by cleavage of the 7,8-double bond of an appropriate vitamin Dderivative (e.g. a precursor compound (I) in which A═ is a group (A-9)),for example by ozonolysis or by successive reaction with potassiumpermanganate and sodium periodate, followed by Wittig-Horner reaction ofthe resulting 8-one with an appropriate ring A precursor, e.g. offormula (XII) ##STR16## (where R⁴ and R⁵ represent O-protectinggroups)--see, for example, Perlman et al., Tetrahedron Letters (1992),33, pp 2937-2940.

In general, either 5,6-cis or 5,6-trans geometry may be present at anyof the various steps described in (C) and (D) above, although it may bepreferred to employ 5,6-trans isomers in the above-mentioned1α-hydroxylation and 22,23-double bond oxidative cleavage reactions.Conversion of 5,6-trans geometry to 5,6-cis is thus most advantageouslyeffected after introduction of the 1α-hydroxyl group.

It will be appreciated that many of the reaction sequences describedabove may also be accomplished using appropriate steroid-5,7-dienes (orsteroid-5-enes which are convertible into such dienes), followed byconversion of the steroid products into the desired vitamin D analogues,e.g. by irradiation with UV light.

In general, O-protecting groups present at the 1α-and/or 3β- positionsmay be removed by, for example, conventional methods such as are welldocumented in the literature. Thus esterifying acyl groups may beremoved by basic hydrolysis, e.g. using an alkali metal alkoxide in analkanol. Etherifying groups such as silyl groups may be removed by acidhydrolysis or treatment with a fluoride salt, e.g. a tetraalkyl ammoniumfluoride. The use of such acid-labile but base-stable protecting groupsmay be of particular advantage during homologation steps to build up adesired side chain, in view of the strongly basic conditions normallyemployed for such reactions.

The following non-limitative examples serve to illustrate the invention.All temperatures are in °C.

Preparation 1

a)20α-Acetoxymethyl-1α-hydroxy-3β-triisopropylsily-loxy-9,10-secopregna-5(E),7-dieneFormula (IV)--A=(A-5). R³ =α-CH₃, R⁴ =(i-Pr)₃ Si , R⁵ =H, L=O.CO.CH₃,Y^(a) =CH₂ !

A solution of tris-triphenylphosphine rhodium chloride (450 mg) inbenzene (30 ml) (or in a 1:1 mixture of benzene and ethanol) is stirredunder hydrogen until no further uptake is observed. A solution of20α-acetoxymethyl-1α-hydroxy-3β-triisopropylsilyloxy-9,10-secopregna-5(E),7,10(19)-triene Formula (V)--A=(A-3), R³ =α-CH₃, R⁴ =(i-Pr)₃ Si, R⁵ =H,L=O.CO.CH₃, Y^(a) =CH₂ --as an alternative the corresponding1α-trimethylsilyl ether may be used! (500 mg) in benzene (30 ml) isadded and the mixture stirred under hydrogen until 1 equivalent ofhydrogen has been taken up (ca 21 ml). The title compounds are purifiedby chromatography the 10(R) and 10(S) isomers may optionally be resolvedat this stage! and have UV Aλ_(max) ca. 243,251 and 261 nm, with ε=ca.35,000; 40,000 and 27,000 respectively.

b) 1α,3β-Bis-triisopropylsilylozy-20α-hydroxymethyl-9,10-secopregna-5(E),7-diene Formula (V)--A=(A-5), R³ =α-CH₃, R⁴ =R⁵=(i-Pr)₃ Si, L=OH, Y^(a) =CH₂ !

The diene from (a) above (ca 500 mg) in dichloromethane (2 ml) istreated with chlorotriisopropylsilane (250 mg) and imidazole (350 mg)and the mixture stirred overnight at room temperature. After work up thecrude bis-silyl ether is dissolved in tetrahydrofuran (10 ml), treatedwith lithium aluminium hydride (100 mg) and stirred at room temperaturefor 1-2 hours. After decomposition of the excess lithium aluminiumhydride (careful addition of saturated aqueous sodium sulphate) thereaction mixture is worked up to afford the title alcohol.

Preparation 2

1α,3β-Bis-triisoipropylsilyloxy-20α-hydroxymethyl-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-4), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=OH, Y^(a) =CH₂ !

The 5(E)-triene starting material in Preparation 1(a) is photoisomerisedin benzene in the presence of phenazine by irradiation for 1 hour, toyield the corresponding 5(Z)-triene. This product is hydrogenated asdescribed in Preparation 1(a) and silylated and de-acetylated asdescribed in Preparation 1(b) to give the title compound. UV λ_(max) ca.243, 251 and 261 nm with ε=ca. 35,000; 40,000 and 27,000 respectively.

The epi (i.e. 20β-hydroxymethyl) compounds corresponding to the productsof Preparations 1 and 2 are prepared by the same procedures startingwith the 20-epi compound20β-acetoxymethyl-1α-hydroxy-3⊖-triisopropylsilyloxy-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =β-CH₃, R⁴ =(i-Pr)₃ Si, R⁵ =H, L=O.CO.CH₃,Y^(a) =CH₂ !. This is itself prepared by isomerisation of the20-aldehyde obtained by ozonolysis of the sulphur dioxide adduct ofvitamin D₂ followed by reduction and 1α-hydroxylation of the 20-epialdehyde.

Preparation 3

a)20α-Acetoxymethyl-1αhydroxy-3β-triisonropylsily-loxy-10-spirocyclopropyl-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-7), R³ =α-CH₃, R⁴ =(i-Pr)₃ Si, R⁵ =H, L=O.CO.CH₃,Y^(a) =CH₂ !

A mixture of zinc/copper couple (1.08 g) and diiodomethane (0.9 ml) inether (6 ml) is heated under reflux with stirring for 40 minutes. Asolution of 20α-acetoxymethyl-1α-hydroxy-3β-triisopropylsilyloxy-9,10-secopregna-5(E), 7,10(19)-triene Formula (V)--A=(A-3), R³ =α-CH₃, R⁴=(i-Pr)₃ Si, R⁵ =H, L=O.CO.CH₃, Y^(a) =CH₂ --as an alternative thecorresponding 1α-trimethylsilyl ether may be used! (ca. 500 mg) in ether(9 ml) is added, and the mixture is stirred and heated under refluxuntil most of the starting material has disappeared (TLC control:usually about 4 hours for the 1α-trimethylsilyl ether, less for the1α-hydroxy compound). The reaction mixture is filtered, the solventremoved and the product chromatographed to remove the remainingdiiodomethane. The title compound has UV λ_(max) ca. 246, 253 and 263nm, with ε=ca. 29,000; 36,000 and 25,000 respectively.

b)1α,3β-Bis-triisopropylsilyloxy-20α-hydroxymethyl-10-spirocyclopropyl-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-7), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=OH, Y^(a) =CH₂ !

The diene from (a) above (ca. 500 mg) in dichloromethane (2 ml) istreated with chlorotriisopropylsilane (250 mg) and imidazole (350 mg)and the mixture stirred overnight at room temperature. After work up thecrude bis-silyl ether is dissolved in tetrahydrofuran (10 ml), treatedwith lithium aluminium hydride (100 mg) and stirred at room temperaturefor 1-2 hours. After decomposition of the excess lithium aluminiumhydride (careful addition of saturated aqueous sodium sulphate) thereaction mixture is worked up to afford the title alcohol.

Preparation 4

1α,3β-Bis-triisopropylsilyloxy-20αhydroxymethyl-10-spirocyclopropyl-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-6) R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=OH, Y^(a) =CH₂ !

The procedure of Preparation 3(a) is repeated starting from thecorresponding 5(Z)-triene, prepared by photoisomerization of the5(E)-triene as described in Preparation 2; the reaction of the5(Z)-triene is somewhat slower than that of the 5(E)-triene. Silylationand de-acetylation as described in Preparation 3(b) gives the titlecompound. UV λ_(max) ca. 246, 253 and 263 nm with ε=ca. 29,000; 36,000and 25,000 respectively.

Preparation 5

1α,3β-Bis-t-butyldimethylsilyloxy-20β-hydroxthyl-19-nor-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-8), R³ =β-CH₃, R⁴ =R⁵ =t-Bu(Me)₂ Si, L=OH, Y^(a) =CH₂!

1α,3β-Bis-t-butyldimethylsilyloxy-20α-formyl-19-nor-9,10-secopregna-5,7-dieneFormula (VII)--A=(A-8), R¹ =α-CH3, R⁴ =R⁵ =t-Bu(Me)₂ Si, Y^(b) =valencebond! obtained as in Tetrahedron Lett. (1992), 33, p 2937, (about 1.5g)is dissolved in benzene (15 ml) and methanol (15 ml) and isomerised bystorage overnight with DBU (400 μl) at 00. The mixture of normal(20α-formyl) and epi (20β-formyl) aldehydes may be resolved bychromatography (silica eluted with 15% benzene in hexane) before orafter reduction of the aldehyde (ca 1 g) in benzene (30 ml) by dropwisetreatment with sodium borohydride, (400 mg) in ethanol (15 ml) at 0°,whereafter the reaction mixture is stirred at 0° for a further 0.5 hour.After work up the product is resolved by chromatography (silica geleluting with benzene or ether in hexane) to yield the title compound.

Preparation 6

a)1α,3β-Bis-triisopropylsilyloxy-23-nor-9,10-seco-chola-5(E),7,10,19-trienicacid, nitrile (mixture of 20-normal and 20- epi isomers) Formula(II)--A=(A-3), R³ =α- and β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y^(a) =CH₂ !

A solution of1α,3β-bis-triisopropylsilyloxy-20(α,β)-tosyloxymethyl-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =α,β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=O.tosyl, Y^(a)=CH₂ ! (1 g) in dimethylsulphoxide (5 ml) containing potassium cyanide(390 mg) was heated at 90° for 2 hours, and the product was extracted(diethyl ether), washed and purified by column chromatography to givethe title nitrile (748 mg). UV (Et₂ O) λ_(max) 267, λ_(min) 229 nm; NMR(CCl₄) δ5.36-6.13 (ABq, 6,7-H's), 4.83 (bs, 19-H's), 4.13-4.46 (m,1,3-H's), 0.53 (s, 18-H's).

b)1α,3β-Bis-triisopropylsilyloxy-23-nor-9,10-seco-chola-5(E),7,10,19-trieniccarboxaldehyde. (mixture of 20- normal and 20- epi isomers) Formula(V)--A=(A-3), R³ =α- and β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=CHO, Y^(a) =CH₂ !

The nitrile from (a) above (480 mg) in hexane (3 ml) was cooled to -78°and treated with diisobutylaluminium hydride (1.4 ml of a 1M solution inheptane). The mixture was stirred at 0° for 1 hour, treated with etherand saturated ammonium chloride solution, and the product isolated byextraction into ether. The crude product had UV (Et₂ O) λ_(max) 270,λ_(min) 229 nm; IR (CCl₄) ν_(max) 1730 cm⁻¹ ; NMR (CCl₄) δ 10.6 (bs,CHO), 5.53-6.23 (ABq, 6,7-H's), 4.76 (bs, 19-H's), 4.16-4.43 (m,1,3-H's), 56 (s, 18-H's).

c)1α,3β-Bis-triisopropylsilyloxy-20(α,β)-(2-hydroxymethyl)-9,10-secopregna-5(E),7,10,19-trieneFormula (V)--A=(A-3), R³ =α- and β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=OH, Y^(a)=(CH₂)₂ !

The aldehyde from (b) above (440 mg) in benzenle (10 ml) was treated at0° with a solution of sodium borohydride (105 mg) in ethanol (10 ml)followed by stirring at room temperature for 45 minutes. After work upthe product was purified by chromatography to give the title compound(380 mg). UV (Et₂ O) λ_(max) 269, λ_(min) 228 nm; IR (CCl₄) ν_(max)3500-3700 cm⁻¹ ; NMR (CCl₄) δ 5.53-6.3 (ABq, 6,7-H's), 4.73 (bs,19-H's), 4.16-4.43 (m, 1,3-H's), 0.56 (s, 18-H's).

The isomers (at C-20) were resolved by careful chromatography of 1.2 gof mixture on silica gel developed with 30% benzene in hexane. The20β-(epi) isomer (145 mg) was less polar and eluted first followed by amixture of isomers and then the 20α-(normal) isomer (360 mg).

d)1α,3β-Bis-triisoropylsilyloxy-20α-(2-bromoethyl)-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =(CH₂)₂!

The normal alcohol from (c) above (200 mg) was stirred at roomtemperature for 2 hours in dichloromethane (5 ml) containingp-toluenesulphonyl chloride (110 mg) and pyridine (243 μl). Sodiumbicarbonate (20 ml of a saturated solution) was added, the stirringcontinued for a further 2 hours, and the reaction mixture worked up. Thecrude tosylate was dissolved in acetonitrile (6.6 ml) anddichloromethane (6.6 ml) containing lithium bromide (317 mg) and 1,8bis-dimethylaminonaphthalene ("proton sponge" 40 mg) and the mixtureheated under reflux at 80° for 30 minutes. The mixture was then cooledand worked up to give the title bromide (261 mg, purified bychromatography). UV (Et₂ O) λ_(max) 267, λ_(min) 228 nm; NMR (CCl₄) δ5.43-6.16 (ABq, 6,7-H's), 4.76 (bs, 19-H's), 4.14-4.45 (m, 1,3-H's),3.16 (m, Cl₂ Br), 0.5 (s, 18-H's).

Preparation 7

a)1α,3β-Bis-triisopropylsilyloxy-20α-bromomethyl-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-5), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =CH₂ !

This compound is prepared from the product of Preparation 1 followingthe procedure of Preparation 6(d).

b)1α,3β-Bis-triisopropylsilyloxy-20α-bromomethy-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-4), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =CH₂ !

This compound is prepared from the product of Preparation 2 followingthe procedure of Preparation 6(d).

c)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-10-spirocyclopropyl-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-7), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =CH₂ !

This compound is prepared from the product of Preparation 3 followingthe procedure of Preparation 6(d).

d)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-10-spirocyclopropyl-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-6), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =CH₂ !

This compound is prepared from the product of Preparation 4 followingthe procedure of Preparation 6(d).

e)1α,3β-Bis-t-butyldimethylsilyloxy-20β-bromomethyl-12-nor-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-8), R³ =β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br. Y^(a) =CH₂ !

This compound is prepared from the product of Preparation 5 followingthe procedure of Preparation 6(d).

Preparation 8

a)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-9,10-secopregna-5(E),7-dieneFormula (V)--A=(A-5), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =(CH₂)₂!

The title compound is prepared from the product of Preparation 7(a)following the procedures of Preparation 6(a)-(d).

b)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-4), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)-₃ Si, L=Br, Y^(a)=(CH₂)₂ !

The title compound is prepared from the product of Preparation 7(b)following the procedures of Preparation 6(a)-(d).

c)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-10-spirocyclopropyl-9,10-secopreana-5(E),7-dieneFormula (V) A=(A-7), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =(CH₂)₂!

The title compound is prepared from the product of Preparation 7(c)following the procedures of Preparation 6(a)-(d).

d)1α,3β-Bis-triisopropylsilyloxy-20α-bromoethyl-10-spirocyclopropyl-9,10-secopregna-5(Z),7-dieneFormula (V)--A=(A-6). R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =(CH₂)₂!

The title compound is prepared from the product of Preparation 7(d)following the procedures of Preparation 6(a)-(d).

e)1α,3β-Bis-t-butyldimethylsilyloxy-20β-bromoethyl-19-nor-9,10-secopregna-5,7-dieneFormula (V)--A=(A-8), R³ =β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =(CH₂)₂!

The title compound is prepared from the product of Preparation 7(e)following the procedures of Preparation 6(a)-(d).

Preparation 9

a)1α,3β-Bis-triisopropylsilyloxy-24-carbamoyl-24-homo-9,10-secochola-5(E),7,10(19),22(E),24(E)-pentaene NH₂ amide of acid of formula (X)--A=(A-3), R³ =α-CH₃, R⁴=R⁵ =(i-Pr)₃ Si, Y=CH═CH--CH═CH!

Lithium aluminium hydride (10 ml of a 1M solution in ether) was stirredat room temperature under an atmosphere of ammonia for 30 minutes. Theresulting suspension was treated with1α,3β-bis-triisopropylsilyloxy-24-ethoxycarbonyl-24-homo-9,10-secochola-5(E),7,10(19),22(E),24(E)-pentaene ethyl ester of acid of formula(X)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y=CH═CH--CH═CH! (250 mg) inether (1 ml) and the mixture was stirred for 10 hours at roomtemperature. The reaction mixture was then cooled to 0°, treated(caution|) with aqueous ethanol (3 ml, 70%), diluted with ether anddried over sodium sulphate. Purification by column chromatography gavethe title compound (180 mg). UV (Et₂ O) λ_(max) 260 nm; IR ν_(max)(CDCl₃) 3520-3000, 1670, 1630, 1580 cm⁻¹ ; NMR (CDCl₃) δ 0.63 (s,18-H's), 3.8-4.7 (m, 1,3-H's), 4.7-5.0 (bs, 19-H's), 5.3-7.3 (m,6,7,22,23,24,24a-H's).

b)1α,3β-Bis-triisopropylsilyloxy-24-cyano-24-homo-9,10-secochola-5(E),7,10(19),22(E),24(E)-pentaeneFormula (II)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y=CH═CH--CH═CH!

Trifluoroacetic anhydride (54 μl) was added dropwise to a stirred,ice-cooled solution of the amide from (a) above in anhydrous dioxan (540μl) containing pyridine (150 μl). The mixture was stirred for 1 hour atroom temperature, diluted with ether, washed successively with water,aqueous hydrochloric acid, saturated aqueous sodium bicarbonate andbrine and then dried. The solvents were removed in vacuo and the productwas isolated by chromatography to give the title compound (115 mg). UV(Et₂ O) λ_(max) 260 nm; IR ν_(max) (CDCl₄) 2100, 1630 cm⁻¹ ; NMR (CDCl₃)δ 0.56 (s, 18-H's), 3.8-4.6 (m, 1,3-H's), 4.6-5.0 (bs, 19-H's), 5.3-7.3(m, 6,7,22,23, 24,24a-H's).

EXAMPLE 1

a)1α,3β-Bis-triisopropylsilyloxy-9,10-secochola-5(E),7,10(19)-triene-24-carbonitrileFormula (II)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Sii, Y=(CH₂)₃ !

A solution of1α,3β-bis-triisopropylsilyloxy-24-tosyloxy-9,10-secochola-5(E),7,10(19)-triene,generated in situ by tosylation of the corresponding 24-ol (480 mg,prepared as described in Example 2(c) of WO 93/09093), in dimethylsulphoxide (2.5 ml) containing potassium cyanide (220 mg) was heated at90° for 50 minutes, cooled and extracted with ethyl acetate. Thethus-obtained product was purified by column chromatography to yield thetitle compound (320 mg). UV (Et₂ O) λ_(max) 267, λ_(min) 236 nm; NMR(CCl₄) δ 5.53-6.3 (ABq, 6,7-H's), 4.8 (s, 19-H's), 0.50 (s, 18-H's).

b)25-Amino-1α,30-bis-triisopropylsilyloxy-9,10-secocholesta-5(E),7,10(19)-trieneFormula (I)--A=(A-3), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Sii,Y=(CH₂)₃!

Tetrahydrofuran (2 ml) was added to cerous chloride (639 mg) at 0°. Theresulting solution was stirred at room temperature for 15 minutes,cooled to -70°, treated with methyl lithium (1.85 ml of a 1.6M solutionin tetrahydrofuran) and stirred briefly at -70°. The nitrile from (a)above (320 mg) in tetrahydrofuran (2.5 ml) was added at -70° to thethus-prepared alkyl cerium reagent and the reaction mixture was stirredfor 1 hour at -70°, briefly warmed to room temperature, cooled to -700°,quenched with concentrated aqueous ammonia (2 ml) and filtered throughCelite, which was thereafter washed with tetrahydrofuran and diethylether. The product was isolated from the combined organic phases andpurified by chromatography (alumina) to give the title compound (235mg). UV (Et₂ O) λ_(max) 268, λ_(min) 228 nm; NMR (CDCl₃) δ 5.58-6.3(ABq, 6,7-H's), 4.83 (s, 19-H's), 0.53 (s, 18-H's).

c)25-Amino-1α,3β-bis-triisopropylsilyloxy-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2). R=H, R¹ =R² =CH₃ R³ =-CH₃, R⁴ =R⁵ =(i-Pr)₃ SiSi,Y=(CH₂)₃ !

A solution of the 5(E) compound from (b) above (188 mg) in benzene (25ml) containing phenazine (98 mg) was irradiated for 50 minutes. Theproduct was worked up and purified by TLC to give the title compound(140 mg). UV (Et₂ O) λ_(max) 260, λ_(min) 222 nm; NMR (CDCl₃) 6 5.66-6.2(ABq, 6,7-H's), 4.7-5.03 (d, 19-H's), 0.50 (s, 18-H's).

d) 25-Amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ R³ =-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ !

The bis-silyl ether from (c) above (60 mg) in tetrahydrofuran (0.556 μl)was desilylated by treatment with tetrabutylammonium fluoride (0.556 μlof a 1M solution in tetrahydrofuran) for 3 hours. The product wasextracted into chloroform, which was then washed twice with water, driedand evaporated in vacuo. The thus-obtained product was purified by twosuccessive TLC's to yield the title compound (10.6 mg). UV (EtOH)λ_(max) 264, λ_(min) 228nm; NMR (CDCl₃) δ 5.66-6.23 (ABq, 6,7-H's),4.8-5.13 (d, 19-H's), 1.1-1.2 (d, 26,27-H's), 0.50 (s, 18-H's) ; IR(CDCl₃) ν_(max) 3600-3350 cm⁻¹ (OH,NH)

EXAMPLE 2

a)1α,3β-Bis-triisopropylsilyloxy-22,23-bisnor-9,10-secochola-5(E),7,10(19)-triene-24-carbonitrile,mixture of 20R and 20S isomers Formula (II)--A=(A-3), R³ =α-and β-CH₃(˜1:1), R⁴ =R⁵ =(i-Pr)₃ Sii, Y=CH₂ !

A solution of1α,3D-bis-triisopropylsilyloxy-20(α,β)-tosyloxymethyl-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =α- and β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Sii, Y^(a) =CH₂,L=tosyloxy! (1 g) in dimethylsulphoxide (5 ml) containing potassiumcyanide (390 mg) was heated at 90° for 2 hours. The product wasextracted with diethyl ether, washed and purified by columnchromatography to give the title compound (748 mg). UV (Et₂ O) λ_(max)267, λ_(min) 229 nm; NMR (CCl₄) δ 5.36-6.13 (ABq, 6,7-H's), 4.83 (bs,19-H's), 4.13-4.46 (m, 1,3-H's), 0.53 (s, 18-H's).

b)25-Amino-1α,3β-bis-triisopropylsilyloxy-23.24-bisnor-9,10-secocholesta-5(E),7,10(19)-triene,mixture of 20R and 20S isomers Formula (I)--A=(A-3), R=H, R¹ =R² =CH₃,R³ =α- and β-CH₃ (˜1.1), R⁴ =R⁵ =(i-Pr)₃ Sii, Y=CH₂ !

A solution of cerous chloride (492 mg, 2 mM) in tetrahydrofuran (2.5 ml)was stirred at room temperature for 1 hour, cooled to -78°, treated withmethyl lithium (2 mM in hexane), and stirred for a further 30 minutes at-78°. A solution of the product from (a) above (262 mg) intetrahydrofuran (1.5 ml) was added, and the reaction mixture was stirredat -78° for 1.5 hours, allowed to warm to room temperature over 2 hours,cooled again to -78°, and worked up as in Example 1(b) to give the titlecompound (170 mg). UV (Et₂ O) λ_(max) 269 nm; NMR (CDCl₃) δ 5.53-6.33(ABq, 6,7-H's), 4.76 (s, 19-H's), 0.53 (s, 18-H's).

c)25-Amino-1α,3β-bis-triisopropylsilyloxy-23.24-bisnor-9,10-secocholesta-5(Z),7,10(19)-triene,mixture of 20R and 20S isomers Formula (I)--A=(A-2), R=H, R¹ =R² =CH₃,R³ =α- and β-CH₃ (˜1:1), R⁴ =R⁵ =(i-Pr)₃ Sii, Y=CH₂ !

A solution of the product from (b) above (170 mg) in benzene (20 ml)containing phenazine (80 mg) was photoisomerised and worked up as inExample 1(c) to give the title compound (90 mg). UV (Et₂ O) λ_(max) 262nm; NMR (CDCl₃) δ 5.63-6.06 (ABq, 6,7-H's), 4.9-5.2 (each s, 19-H's),1.4 (s, gem CH₃ 's), 0.50 (s, 18-H's).

d)25-Amino-1α,3β-dihydroxy-23.24-bisnor-9,10-secocholesta-5(Z),7,10,(19)-triene,mixture of 20R and 20S isomers Formula (I)--A=(A-2), R=H, R¹ =R² =CH₃,R³ =α-and β-CH₃ (˜1:1), R⁴ =R⁵ =H, Y=CH₂ !

A solution of the product from (c) above (90 mg) in tetrahydrofuran (0.5ml) was stirred with tetrabutylammonium fluoride (0.38 ml of a 1Msolution in tetrahydrofuran) overnight. Monitoring by TLC showed thatunchanged starting material remained, so the mixture was treated withfurther tetrabutylammonium fluoride (0.65 ml) and stirred for a further3 hours. The mixture was worked up and the product was isolated andpurified by column chromatography on alumina (twice) to give the titlecompound. UV (EtOH) λ_(max) 263 nm; IR (CDCl₃) ν_(max) 3600-3340 cm⁻¹(OH, NH); NMR (CDCl₃) δ 5.56-6.23 (ABq, 6,7-H's), 4.9-5.23 (each s,19-H's), 1.03, 1.23, 1.36 (m, 21-CH₃, gem CH₃ 's), 0.56 (s, 18-H's)

EXAMPLE 3

a)25-Acetamido-1α,3β-bis-triisopropylsilyloxy-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃Sii, Y=(CH₂)₃ !

A solution of the product from Example 1(c) (60 mg) in methylenechloride (1 ml) was treated with acetic anhydride (290 μl) and pyridine(290 μl) and the resulting mixture was stirred at room temperature for3.5 hours then treated with aqueous sodium bicarbonate. After a further2 hours the mixture was worked up and the product was isolated by TLC togive the title compound (42 mg). UV (Et₂ O) λ_(max) 261, λ_(min) 225 nm;IR (CCl₄) 3420, 3300 (NH), 1670 (C=0) cm⁻¹ ; NMR (CCl₄) δ 5.96-6.1 (ABq,6,7-H's), 4.76, 5.06 (each s, 19-H's), 1.76 (s, COCH₃), 1.23 (s, gem CH₃'s), 0.58 (s, 18-H's).

b) 25-Acetamido-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CO R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₃ !

A solution of the bis-silyl ether from (a) above (42 mg) intetrahydrofuran (0.37 ml) was treated with tetrabutylammonium fluoride(0.36 ml of a 1M solution in tetrahydrofuran). The resulting mixture wasstirred at room temperature for 2 hours, treated with furthertetrabutylammonium fluoride solution (0.1 ml), stirred for 3 hours andworked up. The product was isolated by TLC to give the title compound(20.2 mg). UV (EtOH) λ_(max) 263, λ_(min) 225 nm; IR (CDCl₃) 3420, 3600(NH, OH), 1660 (C=0) cm⁻¹ ; NMR (CDCl₃) δ 5.7-6.3 (ABq, 6,7-H's), 4.8,5.06 (each s, 19-H's), 1.83 (s, COCH₃), 1.23 (s, gem CH3's), 0.83, 0.9(d, 21-H's), 0.58 (s, 18-H's).

EXAMPLE 4

a)1α,3β-Bis-triisopropylsilyloxy-20-epi-9,10-secochola-5(E),7,10(19)-triene-24-carbonitrileFormula (II) A=(A-3-, R³ =β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y=(CH₂)₃ !

Acetonitrile (0.32 ml) in tetrahydrofuran (2 ml) was added dropwise at-78° to a solution of butyl, lithium (3.75 ml) of a 1.6M solution inhexane) and tetrahydrofuran (4 ml). After 50 minutes storage at 78° allbut a 0.38 mMole portion of the solution (presumed to contain a total of6 mMoles) was expelled and the remaining portion treated with a solutionof 1α,3β-bis-triisopropylsilyoxy-20β-bromoethyl-9,10-secopregna-5(E),7,10(19)-triene Formula (V)--A=(A-3),R³ =β-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si, L=Br,Y=(CH₂)₂ ! (100 mg) in tetrahydrofuran (2.05 ml). After 1.5 hoursstorage at -780° (starting material no longer present by TLC), thereaction mixture was treated with aqueous ammonium chloride and theproduct extracted into ether. The crude product was combined withsimilar material from a second reaction (carried out as above on 172 mgbromide) and the product purified by chromatography to give the titlecompound (193 mg). (UV (Et₂ O) λ_(max) 269, λ_(min) 228 nm; NMR (CCl₄) δ0.53 (s,18-H's), 4.8 (s, 19-H's), 5.56-6.3 (ABq, 6,7-H's).

b)25-Amino-1α,3β-bis-triisopropylsilylozy-20-epi-9,10-secocholesta-5(E),7,10(19)-trieneFormula (I)--A=(A-3), R=H, R¹ =R² =CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y=(CH₂)₃ !

A solution of cerous chloride in tetrahydrofuran was treated at 0° withsufficient methyl lithium (1.8 ml of a ?M! solution in hexane) toproduce a persistent yellow colour. The solution was cooled to -78°, afurther portion of methyl lithium (1.35 ml) was added and the mixturewas kept at -78° for 40 minutes to complete formation of theorganocerium reagent. The nitrile from (a) above (196 mg in 3 mltetrahydrofuran) was added at -78° and the reaction mixture was stirredat that temperature for an additional 60 minutes, warmed to -40°, cooledto -78° and treated with ammonium hydroxide. The crude product wasfiltered through celite (methylene chloride/diethyl ether) and purifiedby chromatography to give the title compound (120 mg). UV (Et₂ O),λ_(max) 269, λ_(min) 228 nm; NMR (CCl₄) δ 0.53 (s, 18-H's), 4.13-4.66(bm,1,3-H's), 4.9 (s, 19-H's), 5.66-6.46 (ABq,6,7-H's), 6.46 (bs, NH's,exchanges with D₂ O).

c)25-Amino-1α,3β-bis-triisopropylsilyloxy-20-epi-9-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃, R³ =β-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si,Y=(CH₂)₃ !

The amine from (b) above (80 mg) was photoisomerised by irradiation for40 minutes in solution in benzene (10.6 ml) contained phenazine (42 mg).Chromotography afforded the title compound (50 mg). UV (Et₂ O) λ_(max)263, λ_(min) 226 nm; NMR (CDCl₃) δ 0.50 (s, 18-H's), 4.06-4.6 (bm,1,3-H's), 4.6. 4.76 (ea. s, 19-H's), 5.53-6.2 (ABq, 6,7-H's), 6.2 (bs,NH's, exchanges with D₂ O).

d)25-Amino-1α,3β-dihydroxy-20-epi-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃, R³ =β-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ !

The silyl ether (52 mg) from (c) above was desilyated by treatment withtetrabutylammonium fluoride (350 μl) in tetrahydrofuran (350 μl)overnight at room temperature. Chromatography gave the title compound(8.7 mg). UV (EtOH) λ_(max) 263-4, λ_(min) 225-6 nm; IR (CHCl₃) 3400,3600cm-¹ (OH, NH); NMR (CDCl₃) δ 0.53 (s, 18-H's), 0.86, 0.76 (d21-H's), 2.03 (bs, NH's, exchanges with D₂ O), 4.06-4.46 (bm, 1,3-H's),4.9, 5.23 (ea. s, 19-H's), 5.76-6.4 (ABq, 6,7-H's).

The compound25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-triene Formula(I)--A =(A-2), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ ! isprepared by similar reaction according to steps (a)-(d) above of theproduct of Preparation 6(d).

The compound 25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(E),7-dieneFormula (I)--A=(A-5), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ !is prepared by similar reaction according to steps (a)-(d) above of theproduct of Preparation 8(a).

The compound 25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7-dieneFormula (I)--A=(A-4), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ !is prepared by similar reaction according to steps (a)-(d) above of theproduct of Preparation 8(b).

The compound25-amino-1α,3β-dihydroxy-10-spirocyclopropyl-9,10-secocholesta-5(E),7-dieneFormula (I)--A=(A-7), R=H, R¹ =R² =CH₃, R³ =α-CH3, R⁴ =R⁵ =H, Y=(CH₂)₃ !is prepared by similar reaction according to steps (a)-(d) above of theproduct of Preparation 8(c).

The compound25-amino-1α,3β-dihydroxy-10-spirocyclopropyl-9,10-secocholesta-5(Z),7-diene(Formula (I)--A=(A-6), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃! is prepared by similar reaction according to steps (a)-(d) above ofthe product of Preparation 8(d).

The compound25-amino-1α,3β-dihydroxy-20-epi-19-nor-9,10-secocholesta-5,7-dieneFormula (I)--A=(A-8), R=H, R¹ =R² =CH₃, R³ =β-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₃ !is prepared by similar reaction according to steps (a)-(d) above of theproduct of Preparation 8(e).

EXAMPLE 5

a)1α,3β-Bis-triisopropylsilyloxy-24-homo-9,10-secochola-5(E),7,10(19)-triene-24-carbonitrileFormula (II)--A=(A-3), R³ =α-CH₃ R⁴ =R⁵ =(i-Pr)³ Si, Y=(CH₂)₄ !

Acetonitrile (0.32 ml) in tetrahydrofuran (2 ml) was added dropwise at-78° to a solution of butyl lithium (3.75 ml of a 1.6M solution inhexane) and tetrahydrofuran (4 ml). After 50 minutes storage at -78° allbut a 0.7 mMole portion of the solution (presumed to contain a total of6 mMoles) was expelled and the remaining portion was treated with asolution of1α,3-bis-triisopropylsilyloxy-24-bromo-9,10-secochola-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y=(CH₂)₃ !(190 mg) in tetrahydrofuran (3.05 ml). After 40 minutes storage at -780°the mixture was allowed to warm to -30°, kept at that temperature for 60minutes (starting material no longer present by TLC), then cooled to-78°. Thereafter the reaction mixture was treated with aqueous ammoniumchloride and the product was extracted into diethyl ether. The crudeproduct was purified by chromatography to give the title compound (156mg). UV (EtOH) λ_(max) 267-8, λ_(min) 228 nm; NMR (CCl₄) δ 0.53 (s,18-H's), 4.96, (s, 19-H's), 5.53-6.26 (ABq, 6,7-H's).

b)25-Amino-1α,3β-bis-triisopropylsilyloxy-24-homo-9,10-secocholesta-5(E),7,10(19)-trieneFormula (I)--A=(A-3), R=H, R¹ =R² =CH₃, R³ =α-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si,Y=(CH₂)₄ !

A solution of cerous chloride (381 mg) in tetrahydrofuran (3 ml) wastreated at 0° with sufficient methyl lithium (1.2 mL of a ?! molarsolution in hexane) to produce a persistent yellow colour. The solutionwas cooled to -78°, a further portion of methyl lithium (1.4 ml) wasadded and the mixture was kept at -78° for 30 minutes to completeformation of the organocerium reagent. The nitrile from (a) above (180mg in 2.05 ml tetrahydrofuran) was added at -78°, and the reactionmixture was stirred at that temperature for an additional 60 minutes,warmed to -30°, cooled to -78°, and treated with aqueous ammoniumhydroxide. The crude product was filtered through Celite (methylenechloride/ diethyl ether) and purified by chromatography to give thetitle compound (125 mg). UV (Et₂ O) λ_(max) 267-8, λ_(min) 227-8 nm; NMR(CCl₄) δ 0.53 (s, 18-H's), 4.8, (s, 19-H's), 5.53-6.26 (ABq, 6,7-H's).

c)25-Amino-1α,3β-bis-triisopropylsilyloxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃,R³ =α-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si,Y=(CH₂)₄ !

The amine from (b) above (125 mg) was photoisomerised by irradiation for40 minutes in solution in benzene (18 ml) containing phenazine (61 mg).Chromatography afforded the title compound (88 mg). UV (Et₂ O) λ_(max)263, λ_(min) 226-7 nm; NMR (CDCl₃) δ 0.53 (s, 18-H's), 4.73, 5.0 (ea. s,19-H's), 5.6-6.1 (ABq, 6,7-H's).

d)25-Amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=(CH₂)₄ !

The silyl ether (40 mg) from (c) above was desilyated by treatment withtetrabutylammonium fluoride (320 μl) in tetrahydrofuran (320 μl) forthree hours at room temperature. Chromatography gave the title compound(8.7 mg). UV (EtOH) λ_(max) 263, λ_(min) 226-7 nm; IR (CHCl₃) ν_(max)3200-3300, 3600 cm⁻¹ (OH, NH); NMR (CDCl₃) δ 0.53 (s, 18-H's), 4.9, 5.2(ea. s, 19-H's), 5.8-6.33 (ABq, 6,7-H's).

e)25-Amino-1α,3β-dihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₄ !

The title compound is prepared by substituting ethyl lithium for methyllithium in (b) above and continuing the remainder of the procedure.

f)25-Amino-1α,3β-dihydroxy-24,26,26,26,27,27,27-heptakis-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ (CH₂)₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₄ !

The title compound is prepared by substituting butyl lithium for methyllithium in (b) above and continuing the remainder of the procedure.

g) 25-Amino-1α,3β,23-trihydroxy-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H, Y=CH₂CHOHCH₂ !

The title compound is prepared by substituting1α,3-bis-triisopropylsilyloxy-23-nor-9,10-secopregna-5(E),7,10(19)-triene-24-carboxaldehydeFormula (VII)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y^(b) =CH₂ ! forthe bromoethyl compound in (a) above and containing the remainder of theprocedure.

25-Amino-lx,30-bis-triisopropylsilyloxy-24,26,27-tris-homo-9,10-secocholesta-5(E),7,10(19),22,24(24a)-pentaeneformula (I)--A=(A-3), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃Si, Y=CH═CH--CH═CH! is prepared by substituting ethyl lithium for themethyl lithium and1α,3β-bis-triisopropylsilyloxy-24-cyano-24-homo-9,10-secochola-5(E),7,10(19),22(E),24(E)-pentaeneFormula (II)--A=(A-3), R¹ =α-CH₃, R⁴ =R⁵ (i-Pr)₃ Si, Y=CH═CH--CH═CH!(Preparation 9 (b)) for the nitrile in (b) above.

Isomerisation and desilylation afford25-amino-1α,3β-dihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19),22,24(24a)-pentaene Formula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³=α-CH₃, R⁴ =R⁵ =OH, Y=CH═CH--CH═CH!.

EXAMPLE 6

25-Acetamido-1α,3β-bis-triisopropylsilyloxy-2A-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃Si, Y=(CH₂)₄ !

The 25-amino compound from Example 5 (c) above (48 mg) was treated withacetic anhydride (0.026 ml) in pyridine (0.26 ml) and methylene chloride(0.8 ml). After 2 hours storage at room temperature the reaction mixturewas cooled, treated with aqueous sodium bicarbonate and stirred for 2hours, following which the product was extracted into ethyl acetate.Chromatography gave title compound (24 mg). UV (Et₂ O) λ_(max) 262-3,λ_(min) 225 nm; IR ν_(max) (CCl₄) 3350, 3220 (NH), 1680 cm⁻¹ (CONH); NMR(CCl₄) δ 0.53 (s, 18-H's), 1.8 (s, OCCH₃), 4.1-4.46 (bm, 1,3-H's), 4.73,5.06, 5.23 (each s, 19-H's, N--H), 5.66-6.36 (ABq, 6,7-H's)

b)25-Acetamido-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₄ !

The silyl ether from (a) above (25 mg) was desilylated by treatment withtetrabutylammonium fluoride (0.030 ml) in tetrahydrofuran (0.30 ml) atroom temperature for 4.5 hours. Chromatography gave the title compound(22 mg). UV (EtOH) λ_(max) 263, λ_(min) 225-6 nm; IR ν_(max) (CHCl₃)3420, 3600 (NH, OH), 1670 cm3¹ (CONH); NMR (CDCl₃) δ 0.56 (s, 18-H's),0.86, 0.93 (d, 21-H's), 1.3 (d, CH_(3')), 1.8 (s, OCCH₃), 4.03-4.4 (bm,1,3-H's), 4.9, 5.1, 5.23 (each s, 19-H's, N--H), 5.8-6.36 (ABq,6,7-H's). 25-Benzamido-1α,3β-bis-trilsocropylsilyloxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneformula (I)--A=-(A-2), R=C₆ H₅ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵=(i-Pr)₃ Si, Y=(CH₂)₄ ! is prepared by use of benzoyl chloride and minormodification (Schotten-Baumann) of the procedure of (a) above and may beconverted by desilylation into25-benzamido-let,30-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneformula (I)--A=(A-2), R=C₆ H₅ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₄ !.

EXAMPLE 7

a)25-Amino-1α,3β-bis-triisopropylsilyloxy-26,27-bis-homo-9,10-secocholesta-5(E),7,10(19)-trien-23-yneFormula (I)--A=(A-3), R=H, R¹ =R² =CH_(3:2), R³ =α-CH₃ R⁴ =R⁵ =(i-Pr)₃Si, Y=CH₂ --C.tbd.C!

A solution of 3-amino-3-ethyl-1-pentyne Formula (VI)--R=H, R¹ =R² =CH₃CH₂, n=O! (1.05 ml) in hexane (10.5 ml) containinghexamethylphosphoramide (0.9 ml) was treated at 0° with butyl lithium(4.5 ml of a 1.4M solution in hexane), then kept with stirring at 5° for30 minutes, followed by 1.25 hours at room temperature. All but 2.5mMole of the solution (presumed to contain 6 mMole of acetylide anion)was expelled. The remaining 2.5 mMole of anion was treated with1α,3β-bis-triisopropylsily-loxy-20α-bromomethyl-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =α-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y^(a) =CH₂ !(200 mg) and the resulting mixture stirred at 35° for 21 hours. Thereaction mixture was then cooled, treated with aqueous ammoniumchloride, and the product was extracted into ether. Chromatography gavethe title compound (68 mg) UV (Et₂ O) λ_(max) 267, λ_(min) 226 nm; NMR(CDCl₄) δ 0.5 (s, 18-H's), 4.83 (S, 19-H's), 5.6-6.36 (ABq, 6,7-H's).

b)25-Amino-1α,3β-bis-triisopropylsilyloxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne Formula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³=α-CH₃ R⁴ =R⁵ =(i-Pr)₃ Si, Y=CH₂ --C.tbd.C!

The product from (a) above (95 mg) was photoisomerized by irradiationfor 30 minutes in solution in benzene (14 ml) containing phenazine (50mg). Chromatography gave the title compound (66.5 mg). UV (Et₂ O)λ_(max) 260-1, λ_(min) 226 nm; NMR (CCl₄) δ 0.50 (S, 18-H's), 4.1-4.43(bm, 1,3-H's), 4.73, 5.03 (each s, 19-H's), 5.9-6.23 (ABq, 6,7-H's).

c)25-Amino-1α,3β-dihydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H R¹ =R² =CH₃ CH₂, R³ =α-CH₃ R⁴ =R⁵ =H, Y=CH₃--C.tbd.C!

The silyl ether from (b) above (67 mg) was desilylated by treatment withtetrabutylammonium fluoride (0.5 ml of a 1M solution in tetrahydrofuran)in tetrahydrofuran (0.5 ml) at room temperature overnight. The productwas extracted into chloroform, washed with water and isolated bychromatography to give the title compound (29 mg). UV (EtOH) λ_(max)262-3, λ_(min) 225 nm; IR (CHCl₃) ν_(max) 3200-3500, 3600 cm-⁻¹ (OH,NH); NMR (CDCl₃) δ 0.53 (s, 18-H's), 0.86-1.23 (m, 21-H's and Me-H's ofEt's), 1.9 (m, N--H's, exchanges with D₂ O), 1.36-1.56 (m, Et-H's),4.03-4.4 (bm, 1,3-H's), 4.86, 5.2 (ea. s, 19-H's), 5.76-6.33 (ABq,6,7-H's).

By substituting1α,3β-bis-triisopropylsilyloxy-20β-bromoethyl-9,10-secopregna-5(E),7,10(19)-trieneFormula (V)--A=(A-3), R³ =β-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, L=Br, Y=(CH₂)₂ !for the steroid starting material in (a) above and following theremainder of the procedure one may prepare25-amino-1α,3β-dihydroxy-20-epi-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-trien-24(24a)-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =β-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₂ --C.tbd.C--!.

By substituting 2-amino-2-methyl-4-pentyne Formula (VI)--R=H, R¹ =R²=CH₃, n=1! for the alkyne in (a) above and following the remainingprocedures one obtains25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trien-24(24a)-yneFormula (1) A=(A-2), R=H, R¹ =R² =CH₃,R³ =α-CH₃, R⁴ =R⁵ =H, Y=CH₂--C.tbd.C--CH₂ !.

EXAMPLE 8

Conversion of alkynylenyl side-chain to alkylenyl

The triene system of any of the steroid alkynes prepared acording toExample 7, preferably having 5(E) configuration, is protected fromhydrogenation by reaction with a diazo dienophile (preferablyphthalazine dione) to form a Diels Alder adduct (between the 6- and19-positions). (GB-A-2114570). The resulting adduct (about 100 mg) in amixture of ethanol (5 ml) and benzene (5 ml) containing fresh platinumon charcoal (5%, 100 mg) and sodium bicarbonate (50 mg) is kept under anatmosphere of hydrogen until 2 molecular equivalents of hydrogen havebeen consumed (about 20 hours). Filtration through Celite and removal ofthe solvents gives substantially pure product. The phthalizine group isthen removed as described in the aforementioned British patent and theresulting 5(E) vitamin may be photoisomerised and the silyl groupsremoved as in Example 7. In this fashion one may obtain25-amino-1α,3β-dihydroxy-20-epi-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I) A=(A-2),R=H, R¹ =R² =CH₃ CH₂, R³ =β-CH₃, R⁴ =R⁵ -=H,Y=(CH₂)₄ ! from product of Example 7 (a).

EXAMPLE 9

a)25-Amino-1α,3β-bis-triisopropylsilyloxy-22-hydroxy-26,27-bis-homo-9,10-secocholesta-5(E),7,10(19)-trien-23-yneFormula (I)--A=(A-3), R=H, R¹ =R² =CH₃ CH₂, R³ =αCH₃, R⁴ =R⁵ =(i-Pr)₃Si, Y=CHOH--C.tbd.C!

A solution of 3-amino-3-ethyl-1-pentyne Formula (VI)--R=H, R¹ =R² =CH₃CH₂, n=0! (0.78 ml) in hexane (6.5 ml) containinghexamethylphosphoramide (0.6 ml) was treated at 5° with butyl lithium (3ml of a 1.4M solution in hexane), then kept with stirring at 5° for 30minutes, followed by 1.25 hours at room temperature. A portion of thesolution (1/5, presumed to contain about 0.75 mMole of acetylide anion)was added at -78° to a solution of1α,3β-bis-triisopropylsilyloxy-20α-formyl-9,10-secopregna-5(E),7,10(19)-trieneFormula (VII)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y^(b) =valencebond! (100 mg) and the resulting mixture stirred while the temperaturewas allowed slowly to rise to 200 (by which time the aldehyde had beenconsumed). The reaction mixture was then cooled to -78°, treated withaqueous ammonium chloride, and the product was extracted into ether.Chromatography gave the title compound (94 mg). TV (Et₂ O) λ_(max)268-9, λ_(min) 227 nm; NMR (CCl₄) δ 0.55 (s, 18-H's), 4.23-4.56 (bm,1,3-H's), 4.83 (s, 19-H's), 5.6-6.33 (ABq, 6,7-H's).

b)25-Amino-1α,3β-bis-triisopropylsilyloxy-22-hydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃Si, Y=CHOH--C.tbd.C!

The product from (a) above (94 mg) was photoisomerized by irradiationfor 40 minutes in solution in benzene (11 ml) containing phenazine (40mg). Chromatography gave the title compound (68 mg). UV (Et₂ O) λ_(max)261-2, λ_(min) 225 nm; NMR (CCl₄) δ 0.53 (s, 18-H's), 4.16-4.5 (bm,1,3-H's), 4.73, 5.1 (each s, 19-H's), 5.73-6.06 (ABq, 6,7-H's).

c)25-Amino-1α,3β,22-trihydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =H.Y=CHOH--C.tbd.C!

The silyl ether from (b) above (68 mg) was desilylated by treatment withtetrabutylammonium fluoride (0.5 ml of a 1M solution in tetrahydrofuran)in tetrahydrofuran (0.5 ml) at room temperature for 16 hours. TLC showedsome starting material so a further portion of tetrabutylammoniumfluoride (0.4 ml) was added and the reaction allowed to continue for afurther 2 hours. The product was extracted into chloroform, washed withwater and isolated by chromatography (2×) followed by partition betweenmethylene chloride and water to give the title compound (18 mg). UV(EtOH) λ_(max) 263-4, λ_(min) 225-6 nm; IR (CDCl₃) ν_(max) 3250-3450,3600 cm⁻¹ (OH, NH); NMR (CDCl₃) δ 0.53 (s, 18-H's), 0.83-1.23 (m, 21-H'sand Me-H's of Et's), 1.83 (m, N--H's?), 1.36-1.56 (m, Et-H's), 4.1-4.5(bm, 1,3-H's), 4.9, 5.23 (ea. s, 19-H's), 5.83-6.36 (ABq, 6,7-H's).

By substituting1α,3β-bis-triisopropylsilyloxy-23-nor-9,10-secopregna-5(E),7,10(19)-triene-24-carboxaldehydeFormula (VII)--A=(A-3), R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃ Si, Y^(b) =CH₂ ! in(a) above and following the subsequent procedure one may prepare25-amino-1a,3p,23-trihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-triene-24(24a)-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =H, Y=CH₂CHOH--C.tbd.C!.

By substituting 1,1-dimethylpropargyl amine Formula (VI)--R=H, R¹ =R²=CH₃, n=0! for the aminoalkyne in (a) above and following the subsequentprocedures one may prepare25-amino-1α,3β,22-trihydroxy-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=CHOH--C.tbd.C!.

d)25-Amino-1α,3β-dihydroxy-22-methoxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃ R⁴ =R⁵ =H,Y=CH(OCH₃)--C.tbd.C!

The title compound is prepared by methylation of25-amino-1α,3β-bis-triisopropylsilyloxy-22-hydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃, R⁴ =R⁵ =(i-Pr)₃Si, Y=CHOH--C.tbd.C! from (b) above using a substantial excess ofpotassium t-butoxide in benzene containing 18-crown-6, followed bycareful addition of methyl iodide (TLC control) and then removing thesilyl groups as in (c) above.

25-Amino-1α,3β-dihydroxy-22-ethoxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yneFormula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃ R⁴ =R⁵ =H,Y=CH(OCH₂ CH₃)--C.tbd.C! and25-amino-1α,3β-dihydroxy-22-propoxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne(Formula (I)--A=(A-2), R=H, R¹ =R² =CH₃ CH₂, R³ =α-CH₃ R⁴ =R⁵ =H,Y=CH(OCH₂ CH₂ CH₃)--C.tbd.C! are prepared as in (d) above by replacementof methyl iodide by ethyl or propyl iodides respectively.

EXAMPLE 10

a)N-ethyl-25-amino-1α,3β-bis-triisopropylsilyloxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I) --A=(A-2), R=CH₃ CH₂, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵=(i-pr)₃ Si, L=Br, Y=CCH₂)₄ !

A solution of25-acetamido-l1,3p-bis-triisopropylsily-loxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-triene Formula (I)--A=(A-2), R=CH₃ CO, R¹ =R² =CH₃, R³ =α-CH₃,R⁴ =R⁵ =(i-Pr)₃ Si, Y=(CH₂)₄ ! prepared as in Example 6 (a) (44 mg) intetrahydrofuran (1.5 ml) containing lithium aluminium hydride (35 mg) isheated under reflux with stirring until the starting material isconsumed (about 2.5 hours by TLC analysis), then cooled and treated witha few drops of water. The reaction mixture is treated with sodiumsulphate, diluted with ether, and the etheral layer is decanted.Evaporation of the solvent affords the title compound.

b)N-ethyl-25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CH₂, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ -=H,Y=(CH₂)₄ !

The title compound is obtained by desilylation of the product of (a)above in similar manner to Example 1 (d).

N-propyl-25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CH₂ CH₂, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵ =H,Y=(CH₂)₄ ! is similarly prepared by substituting25-propionamido-1α,3β-bis-triisopropylsilyloxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trieneFormula (I)--A=(A-2), R=CH₃ CH₂ CO, R¹ =R² =CH₃, R³ =α-CH₃, R⁴ =R⁵=(i-Pr)₃ Si, Y=(CH₂)₄ ! (prepared by substituting propionyl chloride inExample 6 and increasing the reaction time to 4 hours) in (a) above andfollowing the remainder of the procedure.

We claim:
 1. A compound of general formula (I) ##STR17## where Rrepresents a hydrogen atom, an aliphatic, cycloaliphatic or araliphaticgroup, or an acyl group comprising an aliphatic, cycloaliphatic,arylaliphatic or aryl group linked to the nitrogen atom by way of acarbonyl group;R¹ and R² are each selected from lower alkyl andcycloalkyl groups or together with the carbon atom to which they areattached form a lower cycloalkyl group; R³ represents a methyl grouphaving α- or β-configuration; Y represents a lower alkylene, alkenyleneor alkynylene group optionally substituted by a hydroxyl, etherifiedhydroxyl or esterified hydroxyl group; and A═ represents acyclohexylidene moiety characteristic of the A-ring of a 1α-hydroxylatedvitamin D or analogue thereof.
 2. A compound as claimed in claim 1wherein R represents a hydrogen atom, a lower alkyl or a lower alkanoylgroup.
 3. A compound as claimed in claim 1 in which R¹ and R² are eachselected from methyl, ethyl, propyl and butyl groups.
 4. A compound asclaimed in claim 1 wherein Y is a straight chain group containing 3-6carbon atoms.
 5. A compound as claimed in claim 4 wherein Y is selectedfrom trimethylene, tetramethylene, pentamethylene, hexamethylene,buta-1,3-dienylene, propynylene, but-1-ynylene and but-2-ynylene.
 6. Acompound as claimed in claim 1 wherein Y carries a hydroxy, etherifiedhydroxy or esterified hydroxy group in a position α-, β- or γ- to thegroup --C(R¹) (R²).NHR or α- to any triple bond present in the group Y.7. A compound as claimed in claim 1 wherein A═ represents one of thegroups ##STR18## where R⁴ and R⁵ are each selected from hydrogen atomsand O-protecting groups.
 8. A compound as claimed in claim 7 wherein R⁴and R⁵ represent etherifying silyl groups.
 9. A compound as claimed inclaim 7 wherein R⁴ and R⁵ are selected from hydrogen atoms andmetabolically labile etherifying or esterifying groups.
 10. A compoundas claimed in claim 1 wherein A═ represents one of the groups ##STR19##11. A 20,20-dimethyl, 20-methylene or 20-spirocyclopropyl analogue of acompound as claimed in claim
 1. 12. A Pharmaceutical compositioncomprising an active compound as claimed in claim 1 in admixture withone or more physiologically acceptable carriers or excipients.
 13. Amethod of treatment of a human or animal subject to promote treatmentand/or prevention of rickets, osteomalacia, osteoporosis,hypoparathyroidism, hypophosphataemia, hypocalcaenia and/or associatedbone disease, hypocalcaemic tetiary, renal failure, renalosteodystraphy, biliary cirrhosis, steatorrhea, secondary hypocalcaemiaand/or associated bone disease, wound healing, fertility control,suppression of parathyroid hormone or management of disorders involvingblood clotting or to combat neoplastic disease, infection, bone disease,autoimmune disease, host-graft reaction, transplant rejection,inflammatory disease, neoplasia, hyperplasia, myopathy, enteropathy,spondylitic heart disease, dermatological disease, hypertension,rheumatoid arthritis, psoriatic arthritis, secondaryhyperparathyroidism, asthma, cognitive impairment or senile dementia,comprising administration to said subject of an effective amount of anactive compound as claimed in claim
 1. 14. A process for the preparationof a compound of general formula (I) as defined in claim 1 whichcomprises one or more of:A) isomerising a 5,6-trans isomer of generalformula (I) to a corresponding 5,6-cis isomer, followed if necessaryand/or desired by removal of any O-protecting groups; B) hydroxylating a1-unsubstituted-5,6-trans analogue of a compound of general formula (I)to prepare a 5,6-trans isomer of general formula (I), followed ifnecessary and/or desired by isomerisation and/or removal of anyO-protecting group; C) reacting a compound containing a precursor forthe desired 17-position side chain in one or more stages and with one ormore reactants serving to form the desired side chain, followed ifnecessary and/or desired by isomerisation and/or removal of anyO-protecting groups; or D) reacting a compound of formula (I) to modifythe substitution pattern about the A═ group, followed if necessaryand/or desired by isomerisation and/or removal of protecting groups. 15.Acompound:25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-23,24-bisnor-9,10-secocholesta-5(Z),7,10(19)-triene;25-acetamido-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-20-epi-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(E),7,diene;25-amino-1α,3β-dihydroxy-9,10-secocholesta-5(Z),7,diene;25-amino-1α,3β-dihydroxy-10-spirocyclopropyl-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-10-spirocyclopropyl-9,10-secocholesta-5(E),7,10(19)-triene;25-amino-1α,3β-dihydroxy-20-epi-19-nor-9,10-secocholesta-5,7-diene;25-amino-1α,3β-dihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-24,26,26,26,27,27,27-heptakis-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-acetamido-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-dihydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;25-amino-1α,3β-dihydroxy-20-epi-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-trien-24(24a)-yne;25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-trien-24(24a)-yne;25-amino-1α,3β-dihydroxy-20-epi-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-amino-1α,3β-trihydroxy-26,27-bis-homo-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;25-amino-1α,3β,23-trihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19)-trien-24(24a)-yne;25-amino-1α,3β,22-trihydroxy-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;25-amino-1α,3β-dihydroxy-22-methoxy-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;25-amino-1α,3β-dihydroxy-22-ethoxy-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;25-amino-1α,3-dihydroxy-22-propoxy-9,10-secocholesta-5(Z),7,10(19)-trien-23-yne;N-ethyl-25-amino-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-triene;25-benzamido-1α,3β-dihydroxy-24-homo-9,10-secocholesta-5(Z),7,10(19)-triene;or25-amino-1α,3β-dihydroxy-24,26,27-tris-homo-9,10-secocholesta-5(Z),7,10(19),22,24(24a)-pentaene.